Abstract 1436: ABCF1 and ABCF2 genetic variants in association with hepatocellular carcinoma (HCC) risk

Background/Aims: ATP-binding cassette (ABC) transporters have been shown to regulate tumor initiating cells in various cancer types and specific genotype associated with cancer risk. ABCF1 was on priority among the ABC transporters because the gene located at 6p21, the chromosome region associated with a number of HCC risk genetic loci including the HLA genes. Its family member ABCF2 was also examined as their expression levels were highly correlated and associated with HCC recurrence.

Subjects and Methods: A total of 300 HCC and 300 healthy blood samples (99.3% and 94.7% Chinese respectively) were prospectively collected with informed consent. All patients had been diagnosed with primary HCC and underwent partial hepatectomy. Clinical information including sex, age, tumor stage and survival outcomes were collected prospectively. Genomic DNA were extracted from blood samples and SNPs were examined by TaqMan genotyping assay, Sequenom MassARRAY platform and direct sequencing.

Results: Sixteen SNPs and three INDELs were examined in ABCF1 and ABCF2 in the germline DNA of 300 HCCs and 300 healthy individuals. Among the 19 loci investigated, ABCF1 rs1264440 (916-99A>G) and rs4148252 (*1delA), ABCF2 rs3823589 (-43+219C>A) and rs75100208 (368-94C>A) were significantly associated with HCC risk (OR: 1.424, 95%CI: 1.03-1.97, P=0.032; OR: 1.446, 95%CI: 1.04-2.00, P=0.026; OR: 1.635, 95%CI: 1.09-2.46, P=0.018; OR: 1.479, 95%CI: 1.09-2.18, P=0.049, respectively). Patients with any two of the four variant genotype, compared with those with all wild type, revealed elevated HCC risks (OR: 1.657, 95%CI: 1.16-2.37, P=0.006). Importantly, patients with all four variant genotypes demonstrated augmented HCC risk (OR: 2.295, 95%CI: 1.27-4.15, P=0.006).

Conclusions: ABCF1 genetic variants rs1264440, rs4148252 and ABCF2 genetic variants rs3823589, rs75100208 were associated with significantly increased HCC risk. Augmented cancer risk was observed among patients possessed all four variant genotypes in ABCF1 and ABCF2. Further mechanistic studies are warranted to comprehend the underlying mechanisms.

Citation Format: Philip Chun Yeung, Kelvin Kwok Chai Ng, Tan To Cheung, Charing Ching-Ning Chong, Paul Bo San Lai, Siu Tim Cheung. ABCF1 and ABCF2 genetic variants in association with hepatocellular carcinoma (HCC) risk [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1436.

Abstract 5514: Therapeutic potential of activated natural killer cells in nasopharyngeal carcinoma

One of the key features of nasopharyngeal carcinoma (NPC) is dense lymphocyte infiltration. Despite elevated lymphocyte populations in tumor microenvironment, these lymphocytes have modest killing activity. One of the possible speculations is constitutive STAT3 overexpression within NPC microenvironment which results in immunosuppression of cytolytic immune cells. Natural killer (NK) cells act as first line defense of innate immunity through cytolytic killing of virus-infected cells and/or cancer cells. Unlike T cells, NK killing does not require antigen presentation and therefore would be effective even for MHC defective cancers. This makes NK therapy attractive in form of autologous and allogeneic transfer.

Here we hypothesized that activated NK cells would show enhanced anti-NPC activity. We also sought to investigate the potential of combined NK with STAT3 inhibitor in NPC treatment. In this study, NK cells from peripheral blood mononuclear cells (PBMC) of healthy donors (N=3) were isolated and expanded. Three Epstein Barr Virus (EBV) positive NPC cell lines (NPC43, C666-1, C17) were employed in this study. Naïve and activated NK cells were subjected to NPC coculture at various effector: target (E:T) cell ratios. In combination treatment with NK cells, a small molecule inhibitor Napabucasin was employed for STAT3 treatment. NK killing activity was assessed through flow cytometry analysis of NPC cell death.

The current study demonstrated significant elevation of NK activation marker expressions after 4 weeks of ex vivo expansion (CD69 34.7±2.3 fold, p=0.002; NKG2D 4.2±0.8 fold, p=0.018). Concomitantly, ex vivo activated NK cells demonstrated augmented killing activity against NPC cells at a dose-dependent manner, compared to their naïve status (p<0.001). In NPC43, net cytotoxicity of expanded NK was 35.5±7.2% compared to naïve NK with only 2.5±4.3% (p=0.003). NPC43 was most sensitive towards NK killing, followed by C666-1, then C17. This corresponds to NPC43’s low PD-L1 protein expression, a known downstream STAT3 target and immune checkpoint molecule. In addition, activated NK could kill chemoresistant NPC cells indiscriminately compared to the paralleled parental cells (18.5±2.3% and 16.1±3.8%, p=0.589). Importantly, augmented NPC43 cell death was observed in combined treatment (47.1±2.1%) compared to single treatment (NK alone: 9.2±6.5%; Napabucasin alone: 25.0±4.5%). In summary, this work demonstrated encouraging therapeutic potential of both NK therapy and in combination with STAT3 inhibitor Napabucasin for NPC treatment.

Citation Format: Shinyee Hui, Kwok Wai Lo, Mingjing Xu, Siu Tim Cheung. Therapeutic potential of activated natural killer cells in nasopharyngeal carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5514.

Progranulin mediates immune evasion of pancreatic ductal adenocarcinoma through regulation of MHCI expression

Immune evasion is indispensable for cancer initiation and progression, although its underlying mechanisms in pancreatic ductal adenocarcinoma (PDAC) are not fully known. Here, we characterize the function of tumor-derived PGRN in promoting immune evasion in primary PDAC. Tumor- but not macrophage-derived PGRN is associated with poor overall survival in PDAC. Multiplex immunohistochemistry shows low MHC class I (MHCI) expression and lack of CD8⁺ T cell infiltration in PGRN-high tumors. Inhibition of PGRN abrogates autophagy-dependent MHCI degradation and restores MHCI expression on PDAC cells. Antibody-based blockade of PGRN in a PDAC mouse model remarkably decelerates tumor initiation and progression. Notably, tumors expressing LCMV-gp33 as a model antigen are sensitized to gp33-TCR transgenic T cell-mediated cytotoxicity upon PGRN blockade. Overall, our study shows a crucial function of tumor-derived PGRN in regulating immunogenicity of primary PDAC.

Immune responses to pancreatic ductal adenocarcinoma can be inhibited by cancer cells. Here the authors show that high levels of progranulin in PDAC inhibits immune responses by reducing MHC class I antigen presentation through enhanced degradation of MHC class I via autophagy.

British Association of Dermatologists National Clinical Audit on the Management of Hidradenitis Suppurativa in the UK

BACKGROUND

The first UK guidelines for the management of hidradenitis suppurativa (HS) were published by the British Association of Dermatologists (BAD) in 2018. The guidelines contained a set of audit criteria.

AIM

To evaluate current HS management against the audit standards in the BAD guidelines.

METHODS

BAD members were invited to complete audit questionnaires between January and May 2020 for five consecutive patients with HS per department.

RESULTS

In total, 88 centres participated, providing data for 406 patients. Disease staging using the Hurley system and disease severity using a validated tool during follow-ups was documented in 75% and 56% of cases, respectively, while quality of life and pain were documented in 49% and 50% of cases, respectively. Screening for cardiovascular disease risk factors was as follows: smoking 75%, body mass index 27% and others such as lipids and diabetes 57%. Screening for depression and anxiety was performed in 40% and 25% of cases, respectively. Support for smokers or obese patients was documented in 35% and 23% of cases. In total, 182 patients were on adalimumab, of whom 68% had documentation of baseline disease severity, and 76% were reported as having inadequate response or contraindications to systemic treatments; 44% of patients continued on adalimumab despite having < 25% improvement in lesion count.

CONCLUSION

UK dermatologists performed well against several audit standards, including documenting disease staging at baseline and smoking status. However, improvements are needed, particularly with regard to screening and management of comorbidities that could reduce the long-term complications associated with HS. A re-audit is required to evaluate changes in practice in the future.

Randomized controlled trial of topical corticosteroid and home-based narrowband ultraviolet B for active and limited vitiligo: results of the HI-Light Vitiligo Trial

BACKGROUND

Evidence for the effectiveness of vitiligo treatments is limited.

OBJECTIVES

To determine the effectiveness of (i) handheld narrowband UVB (NB-UVB) and (ii) a combination of potent topical corticosteroid (TCS) and NB-UVB, compared with TCS alone, for localized vitiligo.

METHODS

A pragmatic, three-arm, placebo-controlled randomized controlled trial (9-month treatment, 12-month follow-up). Adults and children, recruited from secondary care and the community, aged ≥ 5 years and with active vitiligo affecting < 10% of skin, were randomized 1 : 1 : 1 to receive TCS (mometasone furoate 0·1% ointment + dummy NB-UVB), NB-UVB (NB-UVB + placebo TCS) or a combination (TCS + NB-UVB). TCS was applied once daily on alternating weeks; NB-UVB was administered on alternate days in escalating doses, adjusted for erythema. The primary outcome was treatment success at 9 months at a target patch assessed using the participant-reported Vitiligo Noticeability Scale, with multiple imputation for missing data. The trial was registered with number ISRCTN17160087 on 8 January 2015.

RESULTS

In total 517 participants were randomized to TCS (n = 173), NB-UVB (n = 169) and combination (n = 175). Primary outcome data were available for 370 (72%) participants. The proportions with target patch treatment success were 17% (TCS), 22% (NB-UVB) and 27% (combination). Combination treatment was superior to TCS: adjusted between-group difference 10·9% (95% confidence interval 1·0%-20·9%; P = 0·032; number needed to treat = 10). NB-UVB alone was not superior to TCS: adjusted between-group difference 5·2% (95% CI - 4·4% to 14·9%; P = 0·29; number needed to treat = 19). Participants using interventions with ≥ 75% expected adherence were more likely to achieve treatment success, but the effects were lost once treatment stopped. Localized grade 3 or 4 erythema was reported in 62 (12%) participants (including three with dummy light). Skin thinning was reported in 13 (2·5%) participants (including one with placebo ointment).

CONCLUSIONS

Combination treatment with home-based handheld NB-UVB plus TCS is likely to be superior to TCS alone for treatment of localized vitiligo. Combination treatment was relatively safe and well tolerated but was successful in only around one-quarter of participants.

An economic evaluation of the randomized controlled trial of topical corticosteroid and home-based narrowband ultraviolet B for active and limited vitiligo (the HI-Light Vitiligo Trial)

BACKGROUND

Economic evidence for vitiligo treatments is absent.

OBJECTIVES

To determine the cost-effectiveness of (i) handheld narrowband ultraviolet B (NB-UVB) and (ii) a combination of topical corticosteroid (TCS) and NB-UVB compared with TCS alone for localized vitiligo.

METHODS

Cost-effectiveness analysis alongside a pragmatic, three-arm, placebo-controlled randomized controlled trial with 9 months' treatment. In total 517 adults and children (aged ≥ 5 years) with active vitiligo affecting < 10% of skin were recruited from secondary care and the community and were randomized 1: 1: 1 to receive TCS, NB-UVB or both. Cost per successful treatment (measured on the Vitiligo Noticeability Scale) was estimated. Secondary cost-utility analyses measured quality-adjusted life-years using the EuroQol 5 Dimensions 5 Levels for those aged ≥ 11 years and the Child Health Utility 9D for those aged 5 to < 18 years. The trial was registered with number ISRCTN17160087 on 8 January 2015.

RESULTS

The mean ± SD cost per participant was £775 ± 83·7 for NB-UVB, £813 ± 111.4 for combination treatment and £600 ± 96·2 for TCS. In analyses adjusted for age and target patch location, the incremental difference in cost for combination treatment compared with TCS was £211 (95% confidence interval 188-235), corresponding to a risk difference of 10·9% (number needed to treat = 9). The incremental cost was £1932 per successful treatment. The incremental difference in cost for NB-UVB compared with TCS was £173 (95% confidence interval 151-196), with a risk difference of 5·2% (number needed to treat = 19). The incremental cost was £3336 per successful treatment.

CONCLUSIONS

Combination treatment, compared with TCS alone, has a lower incremental cost per additional successful treatment than NB-UVB only. Combination treatment would be considered cost-effective if decision makers are willing to pay £1932 per additional treatment success.

Abstract 2345: Statin use associated with reduced risk of hepatocellular carcinoma recurrence following liver resection: A systematic review and meta-analysis

The effect of statins in preventing hepatocellular carcinoma (HCC) recurrence after curative liver resection has been controversial. Some retrospective studies identified perioperative use of statins was associated with significantly lower risk of HCC recurrence and improve recurrence-free survival (RFS) after liver resection, among patients with or without chronic hepatitis viral infection in multivariate survival analysis. However, a recent single-center study enrolled 430 cases in Taiwan revealed that the protective effect of statins was only significant in univariate analysis but not significant in multivariate analyses. To evaluate the effect of statins on the risk of HCC recurrence after curative liver resections, we performed a systematic review and meta-analysis on this topic. A systematic search of Medline, Embase, and Web of Science was conducted through December 2019. Studies were included if they evaluated perioperative exposure to statins, reported the recurrence of HCC after curative resection, and reported hazard ratios (HR) of multivariable analysis by Cox proportional hazards model. Summary HR estimates with 95% confidence intervals (CI) were calculated using the random-effects model. The analysis included 5 studies reporting the recurrence of HCC among 8,586 patients after liver resection, in which 411 of them received perioperative statins treatments. A meta-analysis of the studies showed a significant (39%) reduction in the risk of HCC recurrence among patients who took statins (adjusted HR, 0.61; 95% CI, 0.49-0.76), with no or little heterogeneity among studies (χ2=5.58, df=4, I2=28%). In conclusion, perioperative statins use may improve recurrence-free survival and decrease the risk of HCC recurrence after curative liver resection. Further prospective studies and larger randomized controlled trials (RCTs) are warranted to validate the conclusion.

Statin usersNon-statin usersAdjusted Hazard RatioStudyTotalTotalWeightIV, Random, 95%CIYear of publicationWu 2012175439437.6%0.68 (0.53-0.87)2012Lee 2016132207831.2%0.66 (0.49-0.90)2016Kawaguchi 2017317037.0%0.34 (0.12-0.75)2017Nishio 20184360014.5%0.42 (0.25-0.71)2018Young 2019304009.8%0.79 (0.41-1.52)2019Total (95% CI)4118175100.0%0.61 (0.49-0.76)Heterogeneity: Tau2=0.02; Chi2=5.58, df=4 (p=0.23); I2=28%Test for overall effect: Z=4.43 (p&lt;0.00001)

Citation Format: Chun Philip Yeung, Siu Tim Cheung, Kwok Chai Kelvin Ng, Bo San Paul Lai, Ching Ning Charing Chong. Statin use associated with reduced risk of hepatocellular carcinoma recurrence following liver resection: A systematic review and meta-analysis [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2345.

Abstract 4180: Therapeutic targeting of STAT3 in nasopharyngeal carcinoma

Cancer stem cells (CSCs) have been reported to associate with resistance, metastasis, recurrence, and related to treatment failure in Nasopharyngeal Carcinoma (NPC). Signal transducer and activator of transcription 3 (STAT3) was associated with CSCs. When activated at tyrosine-705 (Y705) and serine-727 (S727) by phosphorylation, STAT3 promotes tumour inflammation. In CSCs, STAT3 was activated independently of upstream modulator, further increases resistance towards chemotherapy. Hence, we aim to investigate the potential of STAT3 as a therapeutic target in NPC. Immunohistochemistry revealed STAT3 activation in 100% primary NPC tissues (P-STAT3 Y705, n=27). Comparable STAT3 status was observed in patient derived xenografts and cell line established xenografts. Western blot analysis of NPC cell lines (C17, NPC43 and C666-1) substantiated P-STAT3 (Y705 and S727) activation status. STAT3 targeting were examined by specific small interfering RNA (siRNA) and cancer stemness inhibitor Napabucasin, both were shown to knockdown STAT3 activation. Napabucasin reduced cell viability, induced cell death, decelerated NPC cell migration, and inhibited STAT3 phosphorylation. Notably, chemoresistant NPC cell line (C666-1 FR) despite showing 300% higher resistance towards standard chemodrug 5-fluorouracil (5-FU), showed comparable sensitivity towards Napabucasin with reference to its parental cells C666-1. This demonstrates feasibility of STAT3 targeted therapy as alternative treatment strategy in overcoming chemoresistance of NPC. Interestingly, despite significant STAT3 knockdown by siRNA approach, minimal effect on cell proliferation and cell death was observed. In addition, Napabucasin was showed to impair NPC stemness properties including colony and spheroid formation. NPC spheroids were observed to have elevated STAT3 and classical cancer stemness markers (ALDH1A1, CD133) comparing the three-dimensional culture to their corresponding cells in two-dimensional culture. ALDH1A1 and CD133 were downregulated when treated with Napabucasin and STAT3 siRNA. RNA-sequencing and real-time qPCR (RT-qPCR) analysis showed significant downregulation of cancer stemness gene, Euchromatic histone-lysine N-methyltransferase 2 (EHMT2), upon Napabucasin treatment, but not with STAT3 siRNA. This work first reports that Napabucasin downregulates EHMT2 in NPC. qPCR analysis also demonstrated overexpressed EHMT2 in NPC spheroids, suggesting EHMT2 role in regulating NPC cancer stemness. Indeed, when treated with Napabucasin, EHMT2 was downregulated in spheroids. These observations indicate specificity of Napabucasin in controlling NPC cancer stemness. Congruent to in vitro data, Napabucasin suppressed tumor growth in vivo, diminished P-STAT3 (Y705) activation, decreased proliferation (Ki67), and elevated apoptosis (cleaved caspase-3). In summary, this work demonstrated promising therapeutic potential of Napabucasin targeting STAT3 and cancer stemness in NPC.

Citation Format: Shinyee Hui, Kwok Wai Lo, Alyssa Ming-Ting Liu, Marcus Hung-Nam Law, Linda Wing-Chi Ng, Peter Tin-Chung Li, Siu Tim Cheung. Therapeutic targeting of STAT3 in nasopharyngeal carcinoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4180.

Abstract 4151: STAT3 regulates chemo-resistance and cancer stemness in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a major global health problem and its treatment outcomes are limited by therapeutic resistance. Cancer stem cells are the roots of tumor growth, recurrence, metastasis and treatment resistance. Signal transducer and activator of transcription 3 (STAT3) is a transcription factor well known to promote carcinogenesis in a number of tumors. The present study aims to investigate the role of STAT3 in HCC. Total STAT3 levels were examined by qRT-PCR in patients with primary HCC who underwent curative partial hepatectomy. Elevated STAT3 levels were significantly associated with poor recurrence-free survival and overall survival of HCC patients (log-rank test, P = 0.019 and 0.008, respectively). Immunohistochemistry (IHC) was performed to determine the activation status of STAT3 in HCC. Phosphorylated (p)-Y705 and p-S727 staining was detected in HCC tissues, albeit with varying patterns of expression. To investigate the efficacy of STAT3-targeted therapeutics in HCC, napabucasin, a cancer stemness inhibitor targeting STAT3-driven gene transcription, and the specific small interfering RNA (siRNA) were examined in HCC cell lines Hep3B, HepG2 and Huh7. Both napabucasin and siRNA prominently downregulated RNA and protein levels of total STAT3 and p-STAT3 of HCC cells. Napabucasin reduced viability, induced death, hindered migration, impaired colony and spheroid formation efficiency of HCC cells, as well as lowered expression levels of the cancer stem cell markers granulin-epithelin precursor (GEP) and CD133 in whole genome RNA sequencing analysis. Notably, napabucasin combined with 5-fluorouracil (5-FU) synergistically inhibited cell proliferation and induced apoptosis, suggesting its potential in sensitizing HCC cells to chemotherapeutic agents. In addition, napabucasin diminished the colony and spheroid formation abilities of chemo-resistant HCC cells (acquired resistance to 5-FU with over 10-fold increase) to a similar extent as their parental counterparts, indicating its potency in targeting chemo-resistant HCC cells via cancer stemness inhibition. Furthermore, napabucasin also suppressed HCC tumor growth in vivo, accompanied with reduced total STAT3 and p-STAT3 levels and proliferation (Ki-67). Overall, the present study highlighted the prognostic significance of STAT3 in HCC, and its functional role in the control of chemo-resistance and cancer stemness in HCC through targeted therapeutics.

Citation Format: Carol Lee, Elaine Yee-Ling OR, Charing Ching-Ning Chong, Tan To Cheung, Iris Ming-Jing Xu, Linda Wing-Chi Ng, Marcus Hung-Lam Law, Peter Tin-Chung Li, Stephen Lam Chan, Anthony Wing-Hung Chan, Philip Chun Yeung, Kelvin Kwok-Chai Ng, Paul Bo-San Lai, Siu Tim Cheung. STAT3 regulates chemo-resistance and cancer stemness in hepatocellular carcinoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4151.

Contaminated and misidentified cell lines commonly use in cancer research

Cell line authentication is important for credibility concern and scientific reproducibility. Authenticated cancer cell lines retain the properties of the cancers of origin and serve valuable resources for medical research. Experimental results commonly will be validated in more than one cell line to avoid specific cell line effect not generalizable to the disease on the whole. The use of appropriate and verified cell lines would therefore be very important in preclinical studies of translational research, bridging basic research to clinics.

STAT3: An Emerging Therapeutic Target for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a major global health problem and its treatment options have been limited. Signal transducer and activator of transcription 3 (STAT3) is a transcription factor important for various cellular processes. Overexpression and constitutive activation of STAT3 have been frequently found in HCC and associated with poor prognosis. Ample evidence has shown that STAT3 plays pivotal roles in the initiation, progression, metastasis and immune suppression of HCC. Thus, STAT3 has attracted attention as a novel therapeutic target in HCC. Clinical trials have investigated STAT3-targeted therapeutics either as monotherapy or in combination with chemotherapeutic agents, immune checkpoint inhibitors and alternative targeted drugs. Some of these studies have yielded encouraging results. Particularly, napabucasin—a cancer stemness inhibitor targeting STAT3-driven gene transcription—has stood out with its promising clinical efficacy and safety profile. Nonetheless, clinical investigations of STAT3-targeted therapies in HCC are limited and more efforts are strongly urged to evaluate their clinical performance in HCC. Here, we provide a comprehensive review of the roles of STAT3 in HCC and follow by comprehensive analysis of STAT3 targeted strategies.

National audit on the management of bullous pemphigoid

BACKGROUND

Bullous pemphigoid (BP) is an autoimmune, subepidermal, blistering condition that typically affects elderly people.

AIM

To undertake a national clinical audit based on standards derived from the British Association of Dermatologists (BAD) clinical guidelines on the management of BP.

METHODS

In 2018, BAD members were invited to submit data for five consecutive adults with BP per centre, who had been under hospital supervision for at least 12 months, in a national audit over an 11-week period.

RESULTS

In total, 123 responders from 120 hospitals provided data for 524 cases. Diagnosis was made either clinically (10.7%; 56 of 524) or through histology with direct immunofluorescence (41.6%; 218 of 524), indirect immunofluorescence (10.3%; 54 of 524) or both (37.4%; 196 of 524). Most patients had very mild baseline disease (63.9%; 225 of 352) with 21.9% (77 of 352) considered mild, 9.8% (31 of 352) moderate and 5.4% (19 of 352) severe. Documentation of diabetes, glycated haemoglobin (HbA1c), blood pressure and hypertension was available for 54.1% (283 of 523), 51% (267 of 524), 44.2% (231 of 522) and 61.5% (321 of 522) of cases, respectively. Oral corticosteroids were commenced in 85.5% (448 of 524) of patients, with 38.4% (172 of 448) of these having documented risk of osteoporosis; data regarding prescription of bone-protection therapies were available for 99.7% (447 of 448) of cases, with 75.6% (338 of 447) of these having a bone-protection prescription. Patient satisfaction was documented in 59.3% (310 of 523) of cases. Systemic treatment was commenced in 95.9% (502 of 524) of cases during the 12-month assessment period, with baseline blood test and follow-up data available for 96.6% (485 of 502) and 95.6% (480 of 502), respectively. Documentation of baseline blood tests was available for 87.4% (424 of 485) of cases, with follow-up tests recorded in 69.8% (335 of 480).

CONCLUSION

Overall, compliance with elements of documentation was moderate or low, whereas standards pertaining to direct care were high.

The ATP-binding cassette transporter ABCF1 is a hepatic oncofetal protein that promotes chemoresistance, EMT and cancer stemness in hepatocellular carcinoma

ATP-binding cassette (ABC) transporters mediate multidrug resistance and cancer stem cell properties in various model systems. Yet, their biological significance in cancers, especially in hepatocellular carcinoma (HCC), remains unclear. In this study, we investigated the function of ABCF1 in HCC and explored its potential as a therapeutic target. ABCF1 was highly expressed in fetal mouse livers but not in normal adult livers. ABCF1 expression was upregulated in HCCs. These results demonstrate that ABCF1 functions as a hepatic oncofetal protein. We further demonstrated elevated ABCF1 expression in HCC cells upon acquiring chemoresistance. Suppression of ABCF1 by siRNA sensitized both parental cells and chemoresistant cells to chemotherapeutic agents. Reversely, ABCF1 overexpression promoted chemoresistance and drug efflux. In addition, overexpression of ABCF1 enhanced migration, spheroid and colony formation and epithelial-mesenchymal transition (EMT) induction. RNA sequencing analysis revealed EMT inducers HIF1α/IL8 and Sox4 as potential mediators for the oncogenic effect of ABCF1 in HCC progression. Together, this study illustrates that ABCF1 is a novel potential therapeutic target for HCC treatment.

Mouse Monoclonal Antibodies Against Progranulin (PGRN/GEP) as Therapeutics in Preclinical Cancer Models

The use of monoclonal antibody (mAb) has become a unique means of targeted therapy for human cancers. mAb-based therapies have shown survival benefits by applying alone or in combination with chemotherapeutics. Being a humanized biomolecule with exquisite target specificity, mAb demonstrated effects in a relatively lower dose range with limited off-target harm to the patients. Nowadays, novel targets involved in tumorigenic mechanisms and biomarkers expressed exclusively on cancer cell surface are being constantly discovered. The potential effects of their specific mAb could be investigated in the preclinical cancer model. In this chapter, we outlined our experimental procedures in determining the feasibility of novel mAb in the preclinical cancer model, with an example of progranulin (PGRN/GEP) mAb against hepatocellular carcinoma (HCC) tumor in mouse model. This chapter included the establishment of subcutaneous and orthotopic HCC tumor in mouse model, the injection of the mouse monoclonal antibody in combination with cytotoxic chemotherapeutics, the assessment of tumor development, and the analyses of the molecular changes of the tumor cells.

Novel biomarkers GEP/ABCB5 regulate response to adjuvant transarterial chemoembolization after curative hepatectomy for hepatocellular carcinoma

BACKGROUND

Transarterial chemoembolization (TACE) is the most commonly used adjuvant therapy for hepatocellular carcinoma (HCC) after curative resection. Responses to TACE are variable due to tumor and patient heterogeneity. We had previously demonstrated that expression of Granulin-epithelin precursor (GEP) and ATP-dependent binding cassette (ABC)B5 in liver cancer stem cells was associated with chemoresistance. The present study aimed to evaluate the association between GEP/ABCB5 expression and response to adjuvant TACE after curative resection for HCC.

METHODS

Patients received adjuvant TACE after curative resection for HCC and patients received curative resection alone were identified from a prospectively collected database. Clinical samples were retrieved for biomarker analysis. Patients were categorized into 3 risk groups according to their GEP/ABCB5 status for survival analysis: low (GEP-/ABCB5-), intermediate (either GEP+/ABCB5- or GEP-/ABCB5+) and high (GEP+/ABCB5+). Early recurrence (recurrence within 2 years after resection) and disease-free survival were analyzed.

RESULTS

Clinical samples from 44 patients who had followed-up for more than 2 years were retrieved for further biomarker analysis. Among them, 18 received adjuvant TACE and 26 received surgery alone. Patients with adjuvant TACE in the intermediate risk group was associated with significantly better overall survival and 2-year disease-free survival than those who had surgery alone (P = 0.036 and P = 0.011, respectively). Adjuvant TACE did not offer any significant differences in the early recurrence rate, 2-year disease-free survival and overall survival for patients in low and high risk groups.

CONCLUSIONS

Adjuvant TACE can only provide survival benefits for patients in the intermediate risk group (either GEP+/ABCB5- or GEP-/ABCB5+). A larger clinical study is warranted to confirm its role in patient selection for adjuvant TACE.

Treatment of advanced hepatocellular carcinoma: immunotherapy from checkpoint blockade to potential of cellular treatment

The absence of potent therapeutic option accounts for the dismal prognosis of advanced hepatocellular carcinoma (HCC) with high mortality and recurrence rate. For a decade, sorafenib is the only approved systemic drug in the first-line setting and warrants as the standard-of-care for HCC in the advanced stage. Given the common failures of chemotherapies and targeted therapies in the field of HCC treatment, promising breakthroughs were eagerly needed and until recently, immunotherapies have opened a new era of anticancer treatment. The liver organ is perceived as "immunotolerant" owing to its functional role, and the hepatic immune balance is found to be deregulated during chronic liver inflammation and HCC tumorigenesis. Restoring a competent immunity by mitigation of immunosuppression signals is a contemporary approach. In this regard, novel immune checkpoint inhibitors have revolutionized cancer pharmacological treatment options with remarkable clinical outcomes in hematologic malignancy and multiple solid tumors including advanced HCC. Nivolumab, an immunotherapeutic agent to block programmed cell death protein 1 (PD-1), showed high efficacy potential for patients progressed with sorafenib and granted accelerated approval by the US Food and Drug Administration (FDA) recently. The development of this class of immunotherapeutic drug is currently based on myriad studies established on the role of T-cell mediated immunosuppression through immune checkpoints. Heterogeneous results have led to further explorations to the profile of oncogenic processes and signaling pathways associated with PD1/PD-L1 axis. Emerging evidence from preclinical studies implicate natural killer (NK) cells as a mediator to the PD-1 checkpoint signaling immunoevasion. The strategy of adopting immunomodulating ability of NK cells by immune checkpoints inhibitors is potential to additive effects in stimulating anticancer immunity. This idea is not entirely newfound but has recently gained prominence because of advances in defining phenotypic heterogeneity of NK cell populations. The physiological significance and synergistic value of NK cells await further investigation in clinical trials. In this review, an overview of the treatment paradigm shift of HCC management is presented. Current knowledge concerning immunological mechanisms of immune checkpoints attributed to T cell is further discussed and relevant ongoing clinical trials are summarized. We proposed that NK cells should be viewed as part of the network of checkpoint immunoevasion and delineate current evidence of translational clinical research in this area. It is conceivable that immune checkpoint inhibitors in combination with NK cell-based therapeutic strategies will be great promise for treatment of advanced HCC.

Establishment and characterization of new tumor xenografts and cancer cell lines from EBV-positive nasopharyngeal carcinoma

The lack of representative nasopharyngeal carcinoma (NPC) models has seriously hampered research on EBV carcinogenesis and preclinical studies in NPC. Here we report the successful growth of five NPC patient-derived xenografts (PDXs) from fifty-eight attempts of transplantation of NPC specimens into NOD/SCID mice. The take rates for primary and recurrent NPC are 4.9% and 17.6%, respectively. Successful establishment of a new EBV-positive NPC cell line, NPC43, is achieved directly from patient NPC tissues by including Rho-associated coiled-coil containing kinases inhibitor (Y-27632) in culture medium. Spontaneous lytic reactivation of EBV can be observed in NPC43 upon withdrawal of Y-27632. Whole-exome sequencing (WES) reveals a close similarity in mutational profiles of these NPC PDXs with their corresponding patient NPC. Whole-genome sequencing (WGS) further delineates the genomic landscape and sequences of EBV genomes in these newly established NPC models, which supports their potential use in future studies of NPC.

The lack of appropriate models restricts pre-clinical research for nasopharyngeal carcinoma (NPC). Here the authors report the development and characterization of NPC patient-derived xenografts (PDXs), and EBV positive NPC cell line from patient tumor, and suggest their potential use in future NPC research.

Granulin epithelin precursor promotes colorectal carcinogenesis by activating MARK/ERK pathway

Background

Granulin epithelin precursor (GEP) is reported to function as a growth factor stimulating proliferation and migration, and conferring chemoresistance in many cancer types. However, the expression and functional roles of GEP in colorectal cancer (CRC) remain elusive. The aim of this study was thus to investigate the clinical significance of GEP in CRC and reveal the molecular mechanism of GEP in CRC initiation and progression.

Methods

The mRNA expression of GEP in CRC cell lines were detected by qRT-PCR. The GEP protein expression was validated by immunohistochemistry in tissue microarray (TMA) including 190 CRC patient samples. The clinicopathological correlation analysis were achieved by GEP expression on TMA. Functional roles of GEP were determined by MTT proliferation, monolayer colony formation, cell invasion and migration and in vivo studies through siRNA/shRNA mediated knockdown assays. The cancer signaling pathway identification was acquired by flow cytometry, western blot and luciferase activity assays.

Results

The mRNA expression of GEP in CRC was significantly higher than it in normal colon tissues. GEP protein was predominantly localized in the cytoplasm and most of the CRC cases demonstrated abundant GEP protein compared with non-tumorous tissues. GEP overexpression was associated with non-rectal location, advanced AJCC stage, regional lymph node and distant metastasis. By Kaplan–Meier survival analysis, GEP abundance served as a prognostic marker for worse survival in CRC patients. GEP knockdown exhibited anti-cancer effect such as inhibiting cell proliferation, monolayer colony formation, cell invasion and migration in DLD-1 and HCT 116 cells and decelerating xenograft formation in nude mice. siGEP also induced G1 cell cycle arrest and apoptosis. Luciferase activity assays further demonstrated GEP activation was involved in MAPK/ERK signaling pathway.

Conclusion

In summary, we compressively delineate the oncogenic role of GEP in colorectal tumorigenesis by activating MAPK/ERK signaling pathway. GEP might serve as a useful prognostic biomarker and therapeutic target for CRC.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1530-7) contains supplementary material, which is available to authorized users.

A Brief Overview of Progranulin in Health and Disease

The purpose of this brief overview of the progranulin protein is to provide a sense of the range and extent of the roles of progranulin in normal physiology and pathology. Progranulin has received attention due to its role in neurodegeneration, where mutation of a single copy of GRN, the gene encoding progranulin, results in frontotemporal dementia, whereas viral delivery of progranulin to the brains of mice exhibiting Parkinson's or Alzheimer's disease phenotypes inhibits the progression of the neurodegenerative phenotypes. Of equal importance, progranulin protects tissues against the harmful effects of poorly controlled inflammation and promotes tissue regeneration after injury at a multitude of sites throughout the body. Progranulin is overexpressed by many types of cancer and contributes to their progression. Given suitable analytical methods and model systems, progranulin offers a wealth of research possibilities.

Hepatic cancer stem cell marker granulin-epithelin precursor and β-catenin expression associate with recurrence in hepatocellular carcinoma

Granulin-epithelin precursor (GEP) has been demonstrated to confer enhanced cancer stem-like cell properties in hepatocellular carcinoma (HCC) cell line models in our previous studies. Here, we aimed to examine the GEP-expressing cells in relation to the stem cell related molecules and stem-like cell properties in the prospective HCC clinical cohort. GEP protein levels were significantly higher in HCCs than the paralleled non-tumor liver tissues, and associated with venous infiltration. GEP^high cells isolated from clinical HCC samples exhibited higher levels of stem cell marker CD133, pluripotency-associated signaling molecules β-catenin, Oct4, SOX2, Nanog, and chemodrug transporter ABCB5. In addition, GEP^high cells possessed preferential ability to form colonies and spheroids, and enhanced in vivo tumor-initiating ability while their xenografts were able to be serially subpassaged into secondary mouse recipients. Expression levels of GEP and pluripotency-associated genes were further examined in the retrospective HCC cohort and demonstrated significant correlation of GEP with β-catenin. Notably, HCC patients with high GEP and β-catenin levels demonstrated poor recurrence-free survival. In summary, GEP-positive HCC cells directly isolated from clinical specimens showed β-catenin elevation and cancer stem-like cell properties.

Abstract 2895: Octamer-4/microRNA-1246 signaling axis drives Wnt/β-catenin activation in liver cancer stem cells

Hepatocellular carcinoma (HCC), the main type of liver cancer in human, is one of the most prevalent and deadly malignancies in the world. Despite advances in therapy, prognosis remains dismal, largely attributed by our limited understanding on information related to the progressive development of the disease, particularly in their cancer-initiating and stem cell-like properties. Wnt/β-catenin signaling is activated in CD133 liver cancer stem cells (CSC), a subset of cells known to be a root of tumor recurrence and therapy resistance in HCC. However, the regulatory mechanism of this pathway in CSCs remains unclear. Here, we show that human miRNA, miR-1246, promotes cancer stemness including self-renewal, drug resistance, tumorigencity and metastasis by activation of Wnt/β-catenin pathway via suppressing the expression of AXIN2 and GSK3β, two key members of the β-catenin destruction complex. This observation was validated by both in vitro and in vivo functional / cell biological studies on HCC cell lines with or without miR-1246 expression modulated by lentiviral based knockdown and overexpression strategies as well as in miR-1246 repressed HCC cells with concomitant expression of wild-type or constitutively active β-catenin. Clinically, high endogenous and circulating miR-1246 was identified in HCC clinical samples and correlated with a worse prognosis. Further functional analysis identified Oct4 to be the direct upstream regulator of miR-1246, which cooperatively drive β-catenin activation in liver CSCs. In conclusion, our findings not only uncover the non-canonical regulation of Wnt/β-catenin in liver CSCs by Oct4/miR-1246 signaling axis, but also provide a novel diagnostic marker as well as therapeutic intervention for HCC.

Citation Format: Stella Chai, Kai-Yu Ng, Man Tong, Eunice Y. Lau, Terence K. Lee, Kwok Wah Chan, Yun Fei Yuan, Tan To Cheung, Siu Tim Cheung, Xiao Qi Wang, Nathalie Wong, Chung Mau Lo, Kwan Man, Xin Yuan Guan, Stephanie K. Ma. Octamer-4/microRNA-1246 signaling axis drives Wnt/β-catenin activation in liver cancer stem cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2895. doi:10.1158/1538-7445.AM2017-2895

Granulin-epithelin precursor interacts with 78-kDa glucose-regulated protein in hepatocellular carcinoma

Background

Granulin-epithelin precursor (GEP) is a secretory growth factor, which has been demonstrated to control cancer growth, invasion, drug resistance and immune escape. Our previous studies and others also demonstrated its potential in targeted therapy. Comprehensive characterization of GEP partner on cancer cells are warranted. We have previously shown that GEP interacted with heparan sulfate on the surface of liver cancer cells and the interaction is crucial for GEP-mediated signaling transduction. This study aims to characterize GEP protein partner at the cell membrane with the co-immunoprecipitation and mass spectrometry approach.

Methods

The membrane fraction from liver cancer model Hep3B was used for capturing binding partner with the specific monoclonal antibody against GEP. The precipitated proteins were analyzed by mass spectrometry. After identifying the GEP binding partner, this specific interaction was validated in additional liver cancer cell line HepG2 by co-immunoprecipitation using GRP78 and GEP antibodies, respectively, as the bait. GRP78 transcript levels in hepatocellular carcinoma (HCC) clinical samples (n = 77 pairs) were examined by real-time quantitative RT-PCR. GEP and GRP78 protein expressions were investigated by immunohistochemistry on paraffin sections.

Results

We identified the GEP-binding protein as 78-kDa glucose-regulated protein (GRP78, also named heat shock 70-kDa protein 5, HSPA5). This interaction was validated in independent HCC cell lines. Increased GRP78 mRNA levels were demonstrated in liver cancer tissues compared with the paralleled liver tissues (t-test, P = 0.002). GRP78 and GEP transcript levels were significantly correlated (Spearman’s correlation, P = 0.001), and the proteins were also detectable in the cytoplasm of liver cancer cells by immunohistochemical staining.

Conclusions

GRP78 and GEP are interacting protein partners in liver cancer cells and may play a role in GEP-mediated cancer progression in HCC.

Compliance with national guidelines on isotretinoin: where are we 2 years since the last audit? Results of the National Isotretinoin Re-Audit 2014

BACKGROUND

In 2010, the British Association of Dermatologists (BAD) published clinical guidelines for the safe introduction and continued use of isotretinoin in patients with acne in the UK. The BAD provides UK dermatologists with a facility for national audit, and it undertook an audit on compliance with these guidelines in 2012.

AIM

To determine current clinical practices relating to use of isotretinoin among dermatologists in the UK (including geographical variations) as measured against BAD standards, and to ascertain any improvement since the 2012 audit.

METHODS

The 2012 isotretinoin audit proforma was used, with additional questions on clinical setting, complaints and litigation. A web-based survey tool was used for data entry and submission, with email invitation to working, UK-based BAD members (n = 1226) in December 2013 and weekly reminders during the 8.5-week data collection period. Responders were requested to enter data for the three most recent consecutive patients (including one male and one female patient) who had completed treatment within the previous 6 months.

RESULTS

In total, 338 (27.6%) respondents provided data on 1013 patients. Serum lipids were checked in 93.4% of patients and documentation of mental health and/or mood state was recorded in 82.1%. Regarding the Pregnancy Prevention Programme (PPP), 91.6% of female patients of childbearing potential had signed the PPP information form, while 93.3% who had followed the PPP had taken pregnancy tests both before and during treatment, and 54.7% had taken a pregnancy test 5 weeks post-treatment.

CONCLUSION

Overall, there is currently good compliance with standards. Certain aspects of care that are less frequently preformed, such as pregnancy testing post-treatment, are highlighted.

Comprehensive characterization of the patient-derived xenograft and the paralleled primary hepatocellular carcinoma cell line

BACKGROUND

Hepatocellular carcinoma (HCC) is an aggressive cancer with high mortality and morbidity worldwide. The limited clinically relevant model has impeded the development of effective HCC treatment strategy. Patient-derived xenograft (PDX) models retain most of the characteristics of original tumors and were shown to be highly predictive for clinical outcomes. Notably, primary cell line models allow in-depth molecular characterization and high-throughput analysis. Combined usage of the two models would provide an excellent tool for systematic study of therapeutic strategies. Here, we comprehensively characterized the novel PDX and the paralleled primary HCC cell line model.

METHODS

Tumor tissues were collected from HCC surgical specimens. HCC cells were sorted for in vivo PDX and in vitro cell line establishment by the expression of hepatic cancer stem cell marker to enhance cell viability and the rate of success on subsequent culture. The PDX and its matching primary cell line were authenticated and characterized in vitro and in vivo.

RESULTS

Among the successful cases for generating PDXs and primary cells, HCC40 is capable for both PDX and primary cell line establishment, which were then further characterized. The novel HCC40-PDX and HCC40-CL exhibited consistent phenotypic characteristics as the original tumor in terms of HBV protein and AFP expressions. In common with HCC40-PDX, HCC40-CL was tumorigenic in immunocompromised mice. The migration ability in vitro and metastatic properties in vivo echoed the clinical feature of venous infiltration. Genetic profiling by short tandem repeat analysis and p53 mutation pattern consolidated that both the HCC40-PDX and HCC40-CL models were derived from the HCC40 clinical specimen.

CONCLUSIONS

The paralleled establishment of PDX and primary cell line would serve as useful models in comprehensive studies for HCC pathogenesis and therapeutics development for personalized treatment.

Telomerase activity and its association with psychological stress, mental disorders, lifestyle factors and interventions: A systematic review

OBJECTIVE

To summarise and discuss the association between telomerase activity and psychological stress, mental disorders and lifestyle factors.

METHOD

A systematic review was carried out to identify prospective or retrospective studies and interventions published up to June 2015 that reported associations between telomerase activity and psychological stress, mental disorders and lifestyle factors. Electronic data bases of PubMed, ProQuest, CINAHL and Google Scholar were searched.

RESULTS

Twenty six studies on humans measured telomerase activity in peripheral blood mononuclear cells (PBMCs) or leukocytes and examined its association with psychological stress, mental disorders and lifestyle factors. Of those studies, three reported significantly decreased telomerase activity in individuals under chronic psychological stress. Interestingly, one of the three studies found that acute laboratory psychological stress significantly increased telomerase activity. Nine studies reported mixed results on association between mental disorders and telomerase activity. Of the nine studies, five reported that major depressive disorder (MDD) was associated with significantly increased telomerase activity. In thirteen out of fourteen studies on lifestyle factors, it was reported that physical exercise, diet micronutrient supplementation, mindfulness meditation, Qigong practice or yoga mediation resulted in increase in telomerase activity. In addition, two studies on animal models showed that depression-like behaviour was associated with decreased hippocampus telomerase activity. Five animal studies showed that physical exercise increased telomerase activity by cell-type-specific and genotype-specific manners.

CONCLUSION

Although multi-facet results were reported on the association between telomerase activity and psychological stress, mental disorders and lifestyle factors, there were some consistent findings in humans such as (1) decreased telomerase activity in individuals under chronic stress, (2) increased telomerase activity in individuals with MDD, and (3) increased telomerase activity in individuals under lifestyle interventions. Animal studies showed that physical exercise increased telomerase activity in specific cell-types. However, the exact mechanisms for the changes in telomerase activity have not been elucidated. We propose conglomerate models connecting chronic psychological stress, depression, mediation and physical exercise to telomerase activation. Several areas for future research are suggested.

Abstract 2874: Regulatory role of miRNA-1246 and Wnt/β-catenin pathway interaction in CD133+ liver cancer stem cells-driven hepatocellular carcinoma

Hepatocellular carcinoma (HCC), the main type of liver cancer in human, is one of the most prevalent and deadly malignancies in the world. Despite advances in therapy, prognosis remains dismal, largely attributed to our limited understanding on information related to the progressive development of the disease, particularly in their cancer-initiating and stem cell-like properties. There is increasing evidence in recent years to support the role of miRNAs in the regulation of cancer stem cell (CSC) maintenance. However, miRNAs in hepatic CSCs remain understudied. Our group has previously identified a functional subset of liver CSCs marked by the CD133 phenotype. Utilizing a comprehensive transcriptome sequencing approach, we recently compared the differential miRNA profiles of CD133+ liver CSCs and CD133- differentiated cells isolated from HCC cells Huh7 and PLC8024, and identified a significant up-regulation of miR-1246 in the CD133+ liver CSC subset. In silico prediction analysis and luciferase reporter assays found miR-1246 to target both GSK-3β and AXIN2, two key players of the Wnt/β-catenin degradation complex. This is particularly interesting as we and others have previously found the Wnt/β-catenin signaling pathway to be significantly deregulated in CD133+ liver cells as well as in HCC. miR-1246 up-regulation was further validated in additional CD133 sorted HCC cells. Expression of miR-1246 and CD133 was also found to positively correlate across a panel of liver cell lines. Functional studies were subsequently performed using lentiviral-based miR-1246 knockdown in Hep3B and Huh7. miR-1246 deregulation was closely associated with an altered ability of HCC cells to proliferate, self-renew, invade, migrate, induce capillary tube formation in endothelial cells and initiate tumor formation in vivo. Notably, reexpression of constitutively active β-catenin in HCC cells with stable miR-1246 repression rescued this altered phenotype. Knockdown of miR-1246 was associated with increased GSK-3β and AXIN2, concomitant with decreased β-catenin expression, as detected by immunofluorescence. TOP/FOP luciferase signal was also significantly down-regulated following miR-1246 suppression in both CD133-expressing Hep3B and Huh7 cells. By in vivo ubiquitylation assay, a higher level of ubiquitinated β-catenin was observed following miR-1246 knockdown in both Hep3B and Huh7 cells suggesting the decrease in β-catenin was a result of its ubiquitylation. Consistently, downstream targets of the Wnt/β-catenin pathway, including cyclin-D1, c-myc and MMP7, were also likewise decreased at the transcriptional level following miR-1246 knockdown. Taken together, we found miR-1246 to be functionally involved in driving CD133+ liver CSCs through activation of the Wnt/β-catenin and its downstream signaling cascade by directly targeting GSK-3β and AXIN2.

Citation Format: Stella Chai, Kai Yu Ng, Man Tong, Siu Tim Cheung, Xin-Yuan Guan, Stephanie Ma. Regulatory role of miRNA-1246 and Wnt/β-catenin pathway interaction in CD133+ liver cancer stem cells-driven hepatocellular carcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2874. doi:10.1158/1538-7445.AM2015-2874

Copy number gain of granulin-epithelin precursor (GEP) at chromosome 17q21 associates with overexpression in human liver cancer

BACKGROUND

Granulin-epithelin precursor (GEP), a secretory growth factor, demonstrated overexpression in various human cancers, however, mechanism remain elusive. Primary liver cancer, hepatocellular carcinoma (HCC), ranks the second in cancer-related death globally. GEP controlled growth, invasion, metastasis and chemo-resistance in liver cancer. Noted that GEP gene locates at 17q21 and the region has been frequently reported to be amplified in subset of HCC. The study aims to investigate if copy number gain would associate with GEP overexpression.

METHODS

Quantitative Microsatellite Analysis (QuMA) was used to quantify the GEP DNA copy number, and fluorescent in situ hybridization (FISH) was performed to consolidate the amplification status. GEP gene copy number, mRNA expression level and clinico-pathological features were analyzed.

RESULTS

GEP DNA copy number determined by QuMA corroborated well with the FISH data, and the gene copy number correlated with the expression levels (n = 60, r = 0.331, P = 0.010). Gain of GEP copy number was observed in 20% (12/60) HCC and associated with hepatitis B virus infection status (P = 0.015). In HCC with increased GEP copy number, tight association between GEP DNA and mRNA levels were observed (n = 12, r = 0.664, P = 0.019).

CONCLUSIONS

Gain of the GEP gene copy number was observed in 20% HCC and the frequency comparable to literatures reported on the chromosome region 17q. Increased gene copy number contributed to GEP overexpression in subset of HCC.

Restoration of natural killer activity in hepatocellular carcinoma by treatment with antibody against granulin-epithelin precursor

Impairment of natural killer (NK) cell activity is an important mechanism of tumor immunoevasion. We have previously shown that expression of granulin-epithelin precursor (GEP) in hepatocellular carcinoma (HCC) cells rendered the cells resistant to NK cell immunosurveillance. Here, we examined whether targeting GEP could rescue NK activity in HCC patients. The current study demonstrated that quantities and activities of NK cells were significantly lower in HCC patients compared with healthy individuals, and were negatively correlated with GEP levels in HCC cells. NK cells demonstrated enhanced expression of the stimulatory receptors natural-killer group 2, member D (NKG2D) and CD69, increased secretion of IFN-γ and perforin, and cytotoxicity against HCC cells upon GEP suppression. Opposite phenotypes of NK cells were observed when GEP was overexpressed in HCC cells. Importantly, GEP blockage by monoclonal antibody A23 restored NK activity in HCC patients and sensitized HCC cells to NK cytotoxicity. Furthermore, A23 induced NK-mediated antibody-dependent cell-mediated cytotoxicity against HCC. In summary, the activity of NK cells in HCC was impaired by GEP expression, which could be rescued by GEP antibody. This study provides new insight for treatments targeting GEP to boost NK activity in HCC patients.

Granulin-epithelin precursor renders hepatocellular carcinoma cells resistant to natural killer cytotoxicity

Immunoevasion is an emerging hallmark of cancer. Impairment of natural killer (NK) cytotoxicity is a mechanism to evade host immunosurveillance. Granulin-epithelin precursor (GEP) is a hepatic oncofetal protein regulating growth, invasion, and chemoresistance in hepatocellular carcinoma (HCC). We examined the role of GEP in conferring HCC cells the ability to evade NK cytotoxicity. In HCC cell lines, GEP overexpression reduced, whereas GEP suppression enhanced sensitivity to NK cytotoxicity. GEP downregulated surface expression of MHC class I chain-related molecule A (MICA), ligand for NK stimulatory receptor NK group 2 member D (NKG2D), and upregulated human leukocyte antigen-E (HLA-E), ligand for NK inhibitory receptor CD94/NKG2A. Functionally, GEP augmented production of soluble MICA, which suppressed NK activation. Matrix metalloproteinase (MMP)2 and MMP9 activity was involved partly in the GEP-regulated MICA shedding from HCC cells. In primary HCCs (n = 80), elevated GEP (P < 0.001), MICA (P < 0.001), and HLA-E (P = 0.089) expression was observed when compared with those in nontumor (n = 80) and normal livers (n = 10). Serum GEP (P = 0.010) and MICA (P < 0.001) levels were higher in patients with HCC (n = 80) than in healthy individuals (n = 30). High serum GEP and/or MICA levels were associated with poor recurrence-free survival (log-rank test, P = 0.042). Importantly, GEP blockade by mAbs sensitized HCC cells to NK cytotoxicity through MICA. In summary, GEP rendered HCC cells resistant to NK cytotoxicity by modulating MICA expression, which could be reversed by GEP blockade using antibody. Serum GEP and MICA levels are prognostic factors and can be used to stratify patients for targeted therapy.

Establishment and characterization of a novel primary hepatocellular carcinoma cell line with metastatic ability in vivo

Background

Hepatocellular carcinoma (HCC) is a highly aggressive and heterogeneous disease. HCC cell lines established from different patients would be useful in elucidating the molecular pathogenesis. However, success of HCC primary culture establishment remains at low rate. We aim to establish and characterize HCC primary culture and the derived cell line.

Methods

Fresh tumor tissues were collected from 30 HCC patients. Culture conditions were optimized for the attachment and growth of the isolated hepatocytes. Granulin-epithelin precursor (GEP), a growth factor reported to associate with cancer stem cell properties, was examined by flow cytometry to elucidate its role on primary culture establishment. The primary cell line was characterized in detail.

Results

Cells isolated from 16 out of 30 HCC cases (53%) had viability more than 70% and were subject to subsequent in vitro culture. 7 out of 16 cases (44%) could give rise to cells that were able to attach and grow in culture. GEP expression levels significantly correlated with the viability of isolated hepatocytes and success rate of subsequent primary culture establishment. Cells from HCC patient 21 grew and expanded rapidly in vitro and was selected to be further characterized. The line, designated HCC21, derived from a Hong Kong Chinese female patient with HCC at Stage II. The cells exhibited typical epithelial morphology and expressed albumin, AFP and HBV antigens. The cell line was authenticated by short tandem repeat analysis. Comparative genome hybridization analysis revealed chromosomal loss at 1p35-p36, 1q44, 2q11.2-q24.3, 2q37, 4q12-q13.3, 4q21.21-q35.2, 8p12-p23, 15q11.2-q14, 15q24-q26, 16p12.1-p13.3, 16q, 17p, 22q and gain at 1q21-q43 in both HCC21 cells and the original clinical tumor specimen. Sequence analysis revealed p53 gene mutation. Subcutaneous injection of HCC21 cells into immunodeficient mice showed that the cells were able to form tumors at the primary injection sites and metastatic tumors in the peritoneal cavity.

Conclusions

The newly established cell line could serve as useful in vitro and in vivo models for studying primary HCC that possess metastasis ability.

Electronic supplementary material

The online version of this article (doi:10.1186/s12935-014-0103-y) contains supplementary material, which is available to authorized users.

Abstract 552: Genetic polymorphisms of the drug transporter ABCB5 associated with advanced liver cancer

Introduction: ATP-Dependent Binding Cassette B5 (ABCB5) is a transmembrane protein which acts as energy-dependent drug efflux transporter to mediate multidrug resistance of human cancer. Genetic polymorphisms in different gene regions of ABC transporters had been reported to associate with different clinical significances. Our lab has reported that ABCB5 mRNA expression levels were associated with recurrence-free survival of hepatocellular carcinoma patients (Cheung et al Gastroenterology 2011).

Aims: To examine the gene sequence of ABCB5 in human liver cancer and investigate the correlation of genetic polymorphisms with expressions and clinico-pathological features.

Methods: Polymerase chain reaction (PCR) amplification and Sanger sequencing approach was used. PCR was performed for a total of 28 exons and exon-intron boundaries of ABCB5 gene using genomic DNA from liver cancer tissues. Genomic blood DNA from the same patient cohort was used to delineate the genetic polymorphism in the tumor as mutation or germline sequence variation.

Results: Twenty liver cancer tissues and blood DNA samples were examined. A total of 40 genetic polymorphisms were observed in human ABCB5 gene, where 4 were novel genetic polymorphisms (G IVS6+17 T in intron 6; T IVS14+50 C in intron 14; T2166 G in exon 18; A4609G in 3’untranslated region of Exon28) and 36 had been reported in NCBI dbSNP database and SNP consortium. The genetic polymorphisms observed in the tumors were identical to their paralleled blood specimens which suggested that ABCB5 polymorphisms were germline sequence variations. An association of the genetic polymorphism (C784A) in Exon8 of ABCB5 gene with expression level of ABCB5 was observed (P=0.025). Variant genotypes (heterozygous C/A and homozygous A/A) were associated with significantly lower mRNA level of ABCB5 compared to wild type genotype (homozygous C/C). Importantly, polymorphism C784A was associated with tumor stage (P=0.002). Variant genotypes (C/A and A/A) were associated with early stage whereas wild type genotype (C/C) was associated with late stage liver cancer.

Summary: ABCB5 polymorphisms were germline sequence variations in liver cancer patients, as identical genetic sequences were demonstrated in the tumors and their paralleled blood samples. Genetic polymorphism C784A was significantly associated with the transcript levels and tumor stage. Further investigation would increase HCC sample size, inclusion of healthy population, and elucidate the functional implication of the polymorphisms.

Citation Format: Idy C.Y. Leung, Wallace C.W. Yip, Phyllis. F.Y. Cheung, Tan To Cheung, Ronnie T.P. Poon, Sheung Tat Fan, Siu Tim Cheung. Genetic polymorphisms of the drug transporter ABCB5 associated with advanced liver cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 552. doi:10.1158/1538-7445.AM2014-552

Abstract 3764: Antibody therapy against granulin-epithelin precursor sensitizes liver cancer to chemotherapy

The novel growth factor granulin-epithelin precursor (GEP, also named progranulin, acrogranin, or PC-derived growth factor) has shown to be upregulated in breast, ovary, prostate, liver and various human cancers. Our group has shown that GEP associated with chemo-resistance, recurrence and cancer stem cell properties in liver cancer [Gastroenterology 2011 and PLoS One 2011]. In the current study, we demonstrated that, both in vivo and in vitro, liver cancer cells that survived after chemotherapeutic agents demonstrated up-regulation of hepatic cancer stem cell marker CD133/GEP/ABCB5, and enhanced cancer stem cell properties, including colony formation and spheroid formation abilities. Importantly, combination of GEP antibody therapy and chemotherapy reversed the phenotypes induced by chemotherapy alone in the liver cancer cells and also the chemo-resistant subpopulations. Notably, combination of GEP antibody and cisplatin resulted in the eradication of all established intrahepatic human xenografts. This preclinical study demonstrated that combination treatment has the potential to be effective therapeutic regimen for GEP positive cancers.

Citation Format: Nicholas Wong, Phyllis Cheung, Chi Wai Yip, Kui Fat Chan, Irene Ng, Sheung Tat Fan, Siu Tim Cheung. Antibody therapy against granulin-epithelin precursor sensitizes liver cancer to chemotherapy. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3764. doi:10.1158/1538-7445.AM2014-3764

Antibody against granulin-epithelin precursor sensitizes hepatocellular carcinoma to chemotherapeutic agents

Granulin-epithelin precursor (GEP) overexpression has been shown in many cancers with functional role on growth, and recently on regulating chemoresistance and cancer stem cell (CSC) properties. Here, we investigate the combined effect of GEP antibody and chemotherapeutic agent. Combination therapy was compared with monotherapy using hepatocellular carcinoma (HCC) cells in vitro and orthotopic liver tumor models in vivo. CD133 and related hepatic CSC marker expressions were investigated by flow cytometry. Antiproliferative and apoptotic effects and signaling mechanisms were examined by immunohistochemistry, flow cytometry, and Western blot analysis. Secretory GEP levels in the serum and culture supernatant samples were measured by ELISA. We demonstrated that HCC cells that survived under chemotherapeutic agents showed upregulation of hepatic CSC markers CD133/GEP/ABCB5, and enhanced colony and spheroid formation abilities. Importantly, GEP antibody sensitized HCC cells to the apoptosis induced by chemotherapy for both HCC cell lines and the chemoresistant subpopulations, and counteracted the chemotherapy-induced GEP/ABCB5 expressions and Akt/Bcl-2 signaling. In human HCC orthotopic xenograft models, GEP antibody treatment alone was consistently capable of inhibiting the tumor growth. Notably, combination of GEP antibody with high dose of cisplatin resulted in the eradication of all established intrahepatic tumor in three weeks. This preclinical study demonstrated that GEP antibody sensitized HCC cells to apoptosis induced by chemotherapeutic agents. Combination treatment with GEP antibody and chemotherapeutic agent has the potential to be an effective therapeutic regimen for GEP-expressing cancers.

Granulin-epithelin precursor interacts with heparan sulfate on liver cancer cells

The first study to demonstrate HS to affect GEP binding on the cell surface.

Granulin-epithelin precursor (GEP) is a pluripotent secretory growth factor which promotes cancer progression in a number of human cancers. However, how cancer cells interact with GEP remains unknown. In this study, we aimed to identify the cell surface-binding partner of GEP on liver cancer cells. Human recombinant GEP (rGEP) was expressed and purified to homogeneity. The rGEP was shown to trigger phosphorylation of AKT and ERK1/2 in liver cancer cells. We demonstrated cell surface attachment of rGEP, which was blocked by prebinding of platelet-derived growth factor-AA, platelet-derived growth factor-BB and fibroblast growth factor-2. Therefore, heparan sulfate (HS) had been reasoned as the binding partner of rGEP. Heparinase digestion validated the role of HS on supporting the attachment. The heparin-binding domain of GEP was mapped to RRH(555-557) in the C-terminal region. Suppression of the HS polymerase exostosin-1 reduced the rGEP binding and rGEP-mediated signaling transduction. Suppression of a specific HS proteoglycan, glypican-3, also showed a partial reduction of rGEP binding and an inhibition on rGEP-mediated activation of AKT. Furthermore, glypican-3 was shown to correlate with the expressions of GEP in clinical samples (Spearman’s ρ = 0.363, P = 0.001). This study identified HS, partly through glypican-3, as a novel binding partner of GEP on the surface of liver cancer cells.

Abstract 4015: Amplification of GEP at chromosome 17q21 and its overexpression in human liver cancer

Amplification of GEP at chromosome 17q21 and its overexpression in human liver cancer

Hermann M.K. Yung, Wallace C.W. Yip, Phyllis F.Y. Cheung and Siu Tim Cheung

Department of Surgery, The University of Hong Kong.

Introduction:

Hepatocellular carcinoma (HCC) is the 3rd most lethal cancer worldwide. Curative treatments, such as surgical resection, are limited to only a small group of patients. Granulin-epithelin precursor (GEP), which is a secretory growth factor, has been shown to enhance the growth, invasion, metastasis and chemo-resistance of HCC. GEP was found to overexpress in tumors compared to the non-tumor counterpart, and the overexpression correlates to poor prognosis in HCC patients. Antibody targeting GEP inhibited tumor growth in vivo. However, the overexpression mechanisms in HCC are not clear.

Hypothesis:

Gene amplification may be one of the mechanisms for GEP overexpression as its locus, 17q21, is frequently amplified.

Method:

Quantitative Microsatellite Analysis (QuMA) was used to determine the copy number alteration of the GEP gene locus. In this method, quantitative PCR was used to quantify the GEP and microsatellite loci. The genomic stable microsatellite loci were used as reference. Copy number variations were determined by normalization of HCC data to the copy numbers of blood samples from healthy donors, which were defined as diploid 2N. GEP mRNA level was quantified by real-time RT-PCR. Correlations between GEP copy number and its mRNA expression level were analyzed.

Results:

GEP DNA copy numbers were quantified in a panel of clinical HCC (n=60). Amplification of GEP locus was observed in 30% (20/60) HCC, and the amplification frequency was comparable to published reports on chromosome 17q. Overall, GEP copy number correlated to the mRNA overexpression levels (n=60, r=0.267, P=0.039). For HCC with GEP gene locus amplification (n=20), tight correlation with GEP expression levels were observed (r=0.646, P=0.002).

Summary:

We showed that GEP gene was frequently amplified in HCC, and this amplification correlates to the expression level of GEP. Fluorescent in situ hybridization (FISH) will be performed to further investigate the amplification status.

Citation Format: Man Kuen Yung, Chi Wai Yip, Phyllis Fung Yi Cheung, Siu Tim Cheung. Amplification of GEP at chromosome 17q21 and its overexpression in human liver cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4015. doi:10.1158/1538-7445.AM2013-4015

Identification of common variants in BRCA2 and MAP2K4 for susceptibility to sporadic pancreatic cancer

Germline mutations in genes that cause hereditary syndromes are highly predisposed to familial pancreatic cancer. However, genetic susceptibility to sporadic pancreatic cancer is largely uncovered. We conducted a two-stage association study on pancreatic cancer that included 981 cases and 1991 controls in the first stage followed by a second stage (2603 cases and 2877 controls). Using an approach based on candidate genes whose roles in pancreatic cancer have been well known, we identified two new susceptibility loci. rs11571836 located in the BRCA2 3'-untranslated region was significantly associated with lower expression of BRCA2 transcript and increased pancreatic cancer risk [odds ratio = 1.30, 95% confidence interval = 1.14-1.47, P = 7.64 × 10(-5)] in a recessive manner. rs12939944 located in the MAP2K4 intron was associated with decreased risk (odds ratio = 0.82, 95% confidence interval = 0.74-0.91, P = 0.0001) in a dominant manner. Our results demonstrate for the first time that common variants in BRCA2 and MAP2K4 are susceptibility to sporadic pancreatic cancer.

CD44+ cancer stem-like cells in EBV-associated nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a unique EBV-associated epithelial malignancy, showing highly invasive and metastatic phenotype. Despite increasing evidence demonstrating the critical role of cancer stem-like cells (CSCs) in the maintenance and progression of tumors in a variety of malignancies, the existence and properties of CSC in EBV-associated NPC are largely unknown. Our study aims to elucidate the presence and role of CSCs in the pathogenesis of this malignant disease. Sphere-forming cells were isolated from an EBV-positive NPC cell line C666-1 and its tumor-initiating properties were confirmed by in vitro and in vivo assays. In these spheroids, up-regulation of multiple stem cell markers were found. By flow cytometry, we demonstrated that both CD44 and SOX2 were overexpressed in a majority of sphere-forming C666-1 cells. The CD44+SOX2+ cells was detected in a minor population in EBV-positive xenografts and primary tumors and considered as potential CSC in NPC. Notably, the isolated CD44+ NPC cells were resistant to chemotherapeutic agents and with higher spheroid formation efficiency, showing CSC properties. On the other hand, microarray analysis has revealed a number of differentially expressed genes involved in transcription regulation (e.g. FOXN4, GLI1), immune response (CCR7, IL8) and transmembrane transport (e.g. ABCC3, ABCC11) in the spheroids. Among these genes, increased expression of CCR7 in CD44+ CSCs was confirmed in NPC xenografts and primary tumors. Importantly, blocking of CCR7 abolished the sphere-forming ability of C666-1 in vitro. Expression of CCR7 was associated with recurrent disease and distant metastasis. The current study defined the specific properties of a CSC subpopulation in EBV-associated NPC. Our findings provided new insights into developing effective therapies targeting on CSCs, thereby potentiating treatment efficacy for NPC patients.

Granulin-epithelin precursor is an oncofetal protein defining hepatic cancer stem cells

Background and Aims

Increasing evidence has suggested that hepatocellular carcinoma (HCC) might originate from a distinct subpopulation called cancer stem cells (CSCs), which are responsible for the limited efficacy of conventional therapies. We have previously demonstrated that granulin-epithelin precursor (GEP), a pluripotent growth factor, is upregulated in HCC but not in the adjacent non-tumor, and that GEP is a potential therapeutic target for HCC. Here, we characterized its expression pattern and stem cell properties in fetal and cancerous livers.

Methods

Protein expression of GEP in fetal and adult livers was examined in human and mouse models by immunohistochemical staining and flow cytometry. Liver cancer cell lines, isolated based on their GEP and/or ATP-dependent binding cassette (ABC) drug transporter ABCB5 expression, were evaluated for hepatic CSC properties in terms of colony formation, chemoresistance and tumorigenicity.

Results

We demonstrated that GEP was a hepatic oncofetal protein that expressed in the fetal livers, but not in the normal adult livers. Importantly, GEP+ fetal liver cells co-expressed the embryonic stem (ES) cell-related signaling molecules including β-catenin, Oct4, Nanog, Sox2 and DLK1, and also hepatic CSC-markers CD133, EpCAM and ABCB5. Phenotypic characterization in HCC clinical specimens and cell lines revealed that GEP+ cancer cells co-expressed these stem cell markers similarly as the GEP+ fetal liver cells. Furthermore, GEP was shown to regulate the expression of ES cell-related signaling molecules β-catenin, Oct4, Nanog, and Sox2. Isolated GEP^high cancer cells showed enhanced colony formation ability and chemoresistance when compared with the GEP_low counterparts. Co-expression of GEP and ABCB5 better defined the CSC populations with enhanced tumorigenic ability in immunocompromised mice.

Conclusions

Our findings demonstrate that GEP is a hepatic oncofetal protein regulating ES cell-related signaling molecules. Co-expression of GEP and ABCB5 further enriches a subpopulation with enhanced CSC properties. The current data provide new insight into the therapeutic strategy.

Hypertrophic pyloric stenosis in a newborn: a diagnostic dilemma

Infants with hypertrophic pyloric stenosis typically present at 2 to 4 weeks of age with nonbilious projectile vomiting. Hypertrophic pyloric stenosis is exceedingly rare in newborn infants and is scarcely reported in literature. Also, the diagnostic criteria for ultrasonographic measurements in newborn infants have yet to be determined. This report is of a newborn infant with hypertrophic pyloric stenosis. The patient presented with high-volume non-bile-stained output from a nasogastric tube and a dilated gastric bubble on abdominal radiograph. Contrast study ruled out intestinal malrotation. Two ultrasound tests showed that the pyloric muscle thickness and pyloric canal length were within normal limits. Subsequent laparotomy showed a thickened pylorus and pyloromyotomy was performed. The patient showed marked improvement in feeding postoperatively. A high index of suspicion is required for newborn infants presenting with gastric outlet obstruction. Ultrasound and contrast studies provide additional information, but definitive diagnosis may only be available intra-operatively.

Granulin-epithelin precursor and ATP-dependent binding cassette (ABC)B5 regulate liver cancer cell chemoresistance

BACKGROUND & AIMS

Chemotherapy is used to treat unresectable liver cancer with marginal efficacy; this might result from hepatic cancer cells with stem cell and chemoresistant features. Gene expression profiling studies have shown that hepatic cancer cells express granulin-epithelin precursor (GEP); we investigated its role in hepatic cancer stem cell functions and chemoresistance.

METHODS

The effects of GEP and drug transporter signaling on chemoresistance were investigated in hepatic cancer stem cells. We analyzed the expression patterns of 142 clinical samples from liver tumors, adjacent nontumorous liver tissue, and liver tissue from patients who did not have cancer.

RESULTS

GEP regulated the expression of the adenosine triphosphate-dependent binding cassette (ABC)B5 drug transporter in liver cancer cells. Chemoresistant cells that expressed GEP had increased levels of ABCB5; suppression of ABCB5 sensitized the cells to doxorubicin uptake and apoptosis. Most cells that expressed GEP and ABCB5 also expressed the hepatic cancer stem cell markers CD133 and EpCAM; blocking ABCB5 reduced their expression. Expression levels of GEP and ABCB5 were correlated in human liver tumor samples. ABCB5 levels were increased in liver cancer cells compared with nontumor liver tissue from patients with cirrhosis or hepatitis, or normal liver tissue. ABCB5 expression was associated with the recurrence of hepatocellular carcinoma after partial hepatectomy.

CONCLUSIONS

Expression of GEP and ABCB5 in liver cancer stem cells is associated with chemoresistance and reduced survival times of patients with hepatocellular carcinoma. Reagents designed to target these proteins might be developed as therapeutics and given in combination with chemotherapy to patients with liver cancer.

Genomic and proteomic biomarkers for diagnosis and prognosis of hepatocellular carcinoma

Hepatocellular carcinoma is one of the most deadly liver malignancies found worldwide, with hepatitis virus infection being the prominent risk factor for this lesion. Patients with hepatocellular carcinoma are usually first diagnosed when in the advanced stage; thus, long-term clinical outcomes are poor and patients have limited treatment options. Currently, surveillance of hepatocellular carcinoma relies upon serological testing of alpha-fetoprotein levels and hepatic ultrasonography, which have low sensitivity and specificity, and are sometimes operator-dependent, respectively. Therefore, discovery of new biomarkers for early and accurate detection of hepatocellular carcinoma would be of great clinical value. Genomic and proteomic approaches are two major laboratory platforms for the identification of candidate hepatocellular carcinoma biomarkers based on profiling and validating with tumor and nontumor clinical samples. Frequently, these diagnostic markers have been found in association with genetic aberrations, protein-level alterations, post-translational modifications and immune functions. With the discovery of these biomarkers, earlier detection of hepatocellular carcinoma in high-risk subjects (e.g., cirrhosis and hepatitis carriers) becomes possible, which will enable clinicians to offer patients better clinical management and more effective treatment modalities.

Abstract 2556: Granulin-epithelin precursor modulates chemo-resistance in liver cancer

Background and Objective: Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and is responsible for 80% of the primary liver tumors in adults. HCC is found to be resistant to most current chemo-therapeutic agents, making the disease as one of the most mortal in the world. There is therefore an urgent demand for better therapeutic approaches. Granulin-epithelin precursor (GEP) was identified as a potential therapeutic target from our genome-wide expression profiles study for HCC. It was an autocrine growth factor with over-expression in most HCCs, and involved in HCCs proliferation, invasion and tumorigenicity. The aim of the current study is to examine the role and signaling mechanism of GEP in chemo-resistance, and if chemo-resistant HCC would response to GEP targeted therapy using GEP monoclonal antibody (mAb).

Methods: HCC cells Hep3B was stably transfected with GEP cDNA for overexpression, and antisense fragment for suppression studies, respectively. Chemo-resistant HCC populations were obtained by selection and expansion of Hep3B cells under different class of chemo-therapeutic agents, including cisplatin, doxorubicin and fluorouracil. The cells were examined for chemotherapy induced apoptosis with chemo-therapeutic agents alone, or in combination with GEP targeted therapy using GEP mAb. The ERK signaling molecules were examined by western blot, and caspases activity by the Caspase-Glo luminescent assay.

Results: The Hep3B transfectants with GEP overexpression demonstrated increased resistance to apoptosis under different class of chemo-therapeutic agents with reference to the parental population. Hep3B cells with GEP suppression resulted in enhanced sensitivity to the chemotherapy induced apoptosis. The Hep3B cells with acquired resistance demonstrated an increment of 8-16 folds in IC50 to cisplatin, doxorubicin and fluorouracil, respectively, with reference to the parental population. The chemoresistant Hep3B cells were responsive to GEP targeted therapy, and combined chemotherapy with GEP targeted therapy demonstrated synergistic effect on apoptosis induction. GEP regulated the ERK pathway including the activation of p-p38 and p-p44/42. GEP targeted therapy alone did not affect the caspases activities, however, combination treatment using the GEP mAb and chemo-therapeutic agents provided a synergistic effect on activation of caspase 3, and magnified the apoptotic effect.

Summary: The present study demonstrated that GEP regulated chemoresistance, and GEP mAb could sensitize both the parental and chemoresistant liver cancer cells to chemo-therapeutic agents. The GEP targeted therapy indicated a new therapeutic approach for chemo-resistant liver cancer patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2556.

Abstract 4246: Granulin-epithelin precursor (GEP) is an oncofetal protein involved in fetal liver development and liver cancer

Background and objectives:

Granulin-epithelin precursor (GEP) is a novel pluripotent growth factor regulating embryo development, wound repair and tumorigenesis. Our group previously has showed that GEP was over-expressed in over 70% of liver cancer. Besides, functional studies demonstrated that GEP controlled liver cancer proliferation, invasion and tumorigenicity. In this study, we aim to examine the time-frame of GEP expression during fetal liver development, and to characterize the properties of GEP-expressing liver cells.

Methods:

GEP expression was examined by immunofluorescence using flow cytometry and immunohistochemistry. The properties of GEP-expressing cells were characterized by measuring the co-expression of GEP and various stem/progenitor cell markers using immunofluorescence and flow cytometry. Correlation of GEP level with the expression of stem/progenitor markers was studied by transfection experiments.

Results:

In murine model, GEP expression was observed to increase gradually from embryonic day (E) 11 to E17, with up to 49% fetal liver cells were GEP positive. Immediately after birth, GEP expression decreased abruptly from day 1, and by day 7, less than 1% neonatal liver cells were GEP positive, and GEP was not detectable in adult liver. In human, fetal liver at 10 weeks old were demonstrated to express GEP protein, while normal adult livers were devoid of GEP-expressing cells. GEP expression was up-regulated in liver cancer cells compared with the adjacent non-tumor liver cells. Moreover, we showed that GEP co-expressed with hematopoietic stem/progenitor cell marker CD34, liver cancer stem cell marker CD326, and stem cell-related signaling molecules β-catenin and Oct4, suggesting a stem/progenitor cell feature of the GEP-expressing cells. Furthermore, up-regulation of GEP level enhanced the expression of β-catenin and Oct4, and suppression of GEP level resulted in decreased expression of these molecules.

Conclusion:

The present data suggests that GEP is an oncofetal protein, and GEP regulates the expression of stem cell-related signaling molecules. This information advances our knowledge on the fundamental role of GEP in fetal liver development and liver carcinogenesis, and provides valuable insights on the use of GEP as a therapeutic target in the treatment of liver cancer.

Category: Tumor Biology

Sub-classification: TB2: stem cell biology/cancer stem cells/developmental oncobiology

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4246.

Bmi1 functions as an oncogene independent of Ink4A/Arf repression in hepatic carcinogenesis

Bmi1 is a polycomb group proto-oncogene that has been implicated in multiple tumor types. However, its role in hepatocellular carcinoma (HCC) development has not been well studied. In this article, we report that Bmi1 is overexpressed in human HCC samples. When Bmi1 expression is knocked down in human HCC cell lines, it significantly inhibits cell proliferation and perturbs cell cycle regulation. To investigate the role of Bmi1 in promoting liver cancer development in vivo, we stably expressed Bmi1 and/or an activated form of Ras (RasV12) in mouse liver. We found that while Bmi1 or RasV12 alone is not sufficient to promote liver cancer development, coexpression of Bmi1 and RasV12 promotes HCC formation in mice. Tumors induced by Bmi1/RasV12 resemble human HCC by deregulation of genes involved in cell proliferation, apoptosis, and angiogenesis. Intriguingly, we found no evidence that Bmi1 regulates Ink4A/Arf expression in both in vitro and in vivo systems of liver tumor development. In summary, our study shows that Bmi1 can cooperate with other oncogenic signals to promote hepatic carcinogenesis in vivo. Yet Bmi1 functions independent of Ink4A/Arf repression in liver cancer development.

A retrospective study of the referral patterns to a vulval clinic: highlighting educational needs in this subspecialty

A retrospective study of the referral patterns to a specialist vulval clinic was performed. A total of 200 clinical records were reviewed of new patients seen between January 2004 and June 2005. A provisional diagnosis was stated in 45.5% of referrals, of which 27.5% had the diagnosis changed at the clinic. The majority of referrals were from general practitioners (GPs) (77%) and smaller proportions from gynaecologists (11%), dermatologists (9%) and others (3%). The most common conditions seen were lichen sclerosus (39%), eczema/lichen simplex (30.5%), lichen planus (11.5%), pain syndromes (10.5%) and others (8.5%). Lichen sclerosus was accurately diagnosed in 54.5% of referrals but for eczema/lichen simplex it was only recognised in 11.5% of referrals. Nine cases of lichen sclerosus had been referred by gynaecologists after histological confirmation, for advice on management. Education of vulval diseases to non-specialists should focus on conditions that they are most likely to encounter and find difficult to manage. This study illustrates an effective method to define what the local teaching requirements are.

New tools for functional genomic analysis

For the past decade, the development of genomic technology has revolutionized modern biological research and drug discovery. Functional genomic analyses enable biologists to perform analysis of genetic events on a global scale and they have been widely used in gene discovery, biomarker determination, disease classification, and drug target identification. In this article, we provide an overview of the current and emerging tools involved in genomic studies, including expression arrays, microRNA arrays, array CGH, ChIP-on-chip, methylation arrays, mutation analysis, genome-wide association studies, proteomic analysis, integrated functional genomic analysis and related bioinformatic and biostatistical analyses. Using human liver cancer as an example, we provide further information of how these genomic approaches can be applied in cancer research.

A rare case of primary omental neuroblastoma and resection of the recurrent tumor by laparoscopy

Neuroblastoma is the most common extracranial solid tumor in children. Primary omental neuroblastoma has never been reported in the English literature. A 4-year-old girl presented with a mobile abdominal mass; primary omental neuroblastoma was diagnosed. There was tumor recurrence after complete tumor resection. She received chemotherapy and underwent laparoscopic resection of the recurrent tumor. There was no tumor recurrence after 1 year of follow-up.

The use of laparoscopy in the management of Littre's hernia in children

Littre's hernia is a rare complication of Meckel's diverticulum. It was originally defined as 'the presence of a Meckel's diverticulum in any hernia sac' by Rieke in 1841. It is difficult to diagnose before surgery. With the advances in the development of laparoscopic surgery in children, diagnosis of this rare condition, together with subsequent repair of Littre's hernia and Meckel's diverticulectomy can be performed by laparoscopy. We herein report the use of laparoscopy in the management of two boys with Littre's hernia, including one with incarcerated hernia.