Bcl2 and Ki67 refine prognostication in luminal breast cancers

A synthetically lethal nanomedicine delivering novel inhibitors of polynucleotide kinase 3'-phosphatase (PNKP) for targeted therapy of PTEN-deficient colorectal cancer

Phosphatase and TENsin homolog deleted on chromosome 10 (PTEN) is a major tumor-suppressor protein that is lost in up to 75% of aggressive colorectal cancers (CRC). The co-depletion of PTEN and a DNA repair protein, polynucleotide kinase 3'-phosphatase (PNKP), has been shown to lead to synthetic lethality in several cancer types including CRC. This finding inspired the development of novel PNKP inhibitors as potential new drugs against PTEN-deficient CRC. Here, we report on the in vitro and in vivo evaluation of a nano-encapsulated potent, but poorly water-soluble lead PNKP inhibitor, A83B4C63, as a new targeted therapeutic for PTEN-deficient CRC. Our data confirmed the binding of A83B4C63, as free or nanoparticle (NP) formulation, to intracellular PNKP using the cellular thermal shift assay (CETSA), in vitro and in vivo. Dose escalating toxicity studies in healthy CD-1 mice, based on measurement of animal weight changes and biochemical blood analysis, revealed the safety of both free and nano-encapsulated A83B4C63, at assessed doses of ≤50 mg/kg. Nano-carriers of A83B4C63 effectively inhibited the growth of HCT116/PTEN^-/- xenografts in NIH-III nude mice following intravenous (IV) administration, but not that of wild-type HCT116/PTEN^+/+ xenografts. This was in contrast to IV administration of A83B4C63 solubilized with the aid of Cremophor EL: Ethanol (CE), which led to similar tumor growth to that of formulation excipients (NP or CE without drug) or 5% dextrose. This observation was attributed to the higher levels of A83B4C63 delivered to tumor tissue by its NP formulation. Our data provide evidence for the success of NPs of A83B4C63, as novel synthetically lethal nano-therapeutics in the treatment of PTEN-deficient CRC. This research also highlights the potential of successful application of nanomedicine in the drug development process.

Targeting PIN1 exerts potent antitumor activity in pancreatic ductal carcinoma via inhibiting tumor metastasis

The human prolyl isomerase PIN1, best known for its association with carcinogenesis, has recently been indicated in the disease of pancreatic ductal adenocarcinoma (PDAC). However, the functions of PIN1 and the feasibility of targeting PIN1 in PDAC remain elusive. For this purpose, we examined the expression of PIN1 in cancer, related paracarcinoma and metastatic cancer tissues by immunohistochemistry and analyzed the associations with the pathogenesis of PDAC in 173 patients. The functional roles of PIN1 in PDAC were explored in vitro and in vivo using both genetic and chemical PIN1 inhibition. We showed that PIN1 was upregulated in pancreatic cancer and metastatic tissues. High PIN1 expression is significantly association with poor clinicopathological features and shorter overall survival and disease‐free survival. Further stratified analysis showed that PIN1 phenotypes refined prognostication in PDAC. Inhibition of PIN1 expression with RNA interference or with all trans retinoic acid decreased not only the growth but also the migration and invasion of PDAC cells through regulating the key molecules of multiple cancer‐driving pathways, simultaneously resulting in cell cycle arrest and mesenchymal‐epithelial transition in vitro. Furthermore, genetic and chemical PIN1 ablation showed dramatic inhibition of the tumorigenesis and metastatic spread and then reduced the tumor burden in vivo. We provided further evidence for the use of PIN1 as a promising therapeutic target in PDAC. Genetic and chemical PIN1 ablation exerted potent antitumor effects through blocking multiple cancer‐driving pathways in PDAC. More potent and specific PIN1 targeted inhibitors could be exploited to treat this aggressive cancer.

BCL2L12: a multiply spliced gene with independent prognostic significance in breast cancer

Background

Alternative splicing is a key process in carcinogenesis and, from a clinical aspect, holds great promises, as alternatively spliced variants have emerged as an untapped source of diagnostic and prognostic markers. Our aim was to assess the prognostic value of three recently recognized splice variants of the apoptosis-related gene, BCL2L12, in breast cancer (BC).

Methods

Total RNA was extracted from breast samples (150 BC and 80 tumor-adjacent normal tissues) and, following cDNA synthesis, a variant-specific qPCR was performed for the expressional quantification of BCL2L12 v.1, v.2 and v.4 transcript variants. Extensive statistical analysis, including bootstrap resampling and internal validation, was conducted in order to evaluate the associations of v.1, v.2 and v.4 expression with patients’ clinopathological and survival data.

Results

All examined BCL2L12 variants were significantly upregulated in BC specimens compared to their non-cancerous counterpart (v.1, p<0.001; v.2, p=0.009; v.4, p=0.004). Increased BCL2L12 v.4 mRNA expression was associated with markers of unfavorable prognosis namely, advanced tumor grade (p=0.002), ER- (p=0.015)/PR- (p<0.001) negativity, Ki-67-positivity (p=0.007) and high NPI (Nottingham prognostic index) score (p=0.033). Moreover, v.4 was significantly overexpressed in women with triple negative BC (TNBC) and HER2-positive tumors compared to those harboring luminal tumors (p<0.001). Survival analysis disclosed that BCL2L12 v.2 overexpression, as a continuous variable ([HR]=0.45, 95% CI=0.17–0.82, p=0.010), is a strong and independent marker of favorable prognosis for BC patients. Interestingly, v.2 retains its prognostic value in patients with Grade II/III ([HR]=0.21, 95% CI=0.05–0.57, p=0.006) or HER2-positive/TNBC tumors ([HR]=0.25, 95% CI=0.05–0.74, p=0.042).

Conclusions

BCL2L12 v.1, v.2, v.4 are aberrantly expressed in BC. Their expressional analysis by cost-effective molecular methods could provide a novel molecular tool for BC management.

Anticancer Effects of Dihydroartemisinin on Human Esophageal Cancer Cells In Vivo

Despite recent advances in chemotherapy and surgical resection, the 5-year survival rate of esophageal cancer still remains at the low level. Therefore, it is very important to discover a new agent to improve the life expectancy of patients with esophageal cancer. Dihydroartemisinin (DHA), a semisynthetic derivative of artemisinin, has recently exhibited promising anticancer activity against various cancer cells. But so far, the specific mechanism remains unclear. We have previously demonstrated that DHA reduced viability of esophageal cancer cells in a dose-dependent manner in vitro and induced cell cycle arrest and apoptosis. Here, we extended our study to further observe the efficacy of DHA on esophageal cancer cells in vivo. In the present study, for the first time, we found that DHA significantly inhibits cell proliferation in xenografted tumor compared with the control. The mechanism was that DHA induced cell apoptosis in both human esophageal cancer cell lines Eca109 and Ec9706 in vivo in a dose-dependent manner. The results suggested that DHA was a promising agent against esophageal cancer in the clinical treatment.

Smad4/Fascin index is highly prognostic in patients with diffuse type EBV-associated gastric cancer

Gastric cancer is a heterogeneous disorder for which predicting clinical outcomes is challenging, although various biomarkers have been suggested. The Smad4 and Fascin proteins are known prognostic indicators of different types of malignancy. Smad4 primarily functions as a key regulator of tumor suppression, whereas Fascin exhibits oncogenic function by enhancing tumor infiltration. A combined marker based on these opposing roles may improve prognostic accuracy in gastric cancer. Smad4 and Fascin expression was assessed in tissue microarrays obtained from 285 primary gastric adenocarcinoma, 201 normal tissue, and 51 metastatic adenocarcinoma samples. A Smad4/Fascin index based on the relative expression of each protein was divided into low- and high-expression groups using receiver operating characteristic curves. We compared normal tissue, primary adenocarcinoma, and metastatic adenocarcinoma in Smad4 and Fascin expression and the differences in clinicopathological findings between low Smad4/Fascin and high Smad4/Fascin expression in gastric adenocarcinoma. High Smad4/Fascin expression was significantly associated with worse outcomes, such as old age, advanced T and N category, large tumor size, high histological grade, lymphatic and vascular invasion, and presence of Epstein-Barr virus (EBV) (all p < 0.05). Univariate and multivariate analyses revealed a significant relationship between disease-free or overall survival and Smad4/Fascin index in diffuse-type or EBV-associated gastric cancer (all p < 0.05). A dual marker system using Smad4 and Fascin may be a reliable indicator for predicting clinical outcomes in patients with diffuse-type or EBV-associated gastric cancer.

Percentage change of primary tumor on 18F-FDG PET/CT as a prognostic factor for invasive ductal breast cancer with axillary lymph node metastasis: Comparison with MRI

We evaluated the prognostic value of quantitative parameters using dual time point (DTP) F-FDG PET/CT (PET/CT) in invasive ductal breast cancer (IDC) with metastatic axillary lymph nodes (ALN) as compared with dynamic contrast-enhanced (DCE) and diffusion-weighted (DW) MRI.Seventy patients with IDC and metastatic ALN were retrospectively registered. Static PET parameters including maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), total lesion glycolysis (TLG) of primary tumor, SUVmax of ALN (SUVALN), and percentage changes (Δ%) in those parameters were measured with DTP PET/CT. From DCE MRI, peak enhancement value, total tumor angio volume, and proportions of kinetic curve types on delayed-phases were investigated. The average apparent diffusion coefficient (ADCavg) was estimated on DWI. To demonstrate the prognostic value of quantitative imaging parameters for recurrence-free survival (RFS), univariate and multivariate analyses were performed using those parameters and clinicohistologic variables.All static PET parameters, %ΔSUVmax, %ΔMTV, and %ΔSUVALN on DTP PET/CT and ADCavg on DWI were significantly predictive for disease recurrence. Of clinicohistologic variables, pathologic tumor (pT) diameter, pathologic ALN stage, tumor grade, and hormonal status also were significantly prognostic. After multivariate analysis, %ΔSUVmax > 25.05 (P = .043), ADCavg ≤ 1016.55 (P = .020), pT diameter > 3 cm (P = .001), and ER negative status (P = .002) were independent prognostic factors for poor outcome.Only %ΔSUVmax of the primary tumor on PET/CT together with ADCavg, pT diameter, and ER status was an independent prognostic factor for predicting relapse in IDC with metastatic ALN. Percentage change of primary tumor on preoperative PET/CT may be a valuable imaging marker for selecting IDC patients that require adjunct treatment to prevent relapse.

BCL2 Regulation according to Molecular Subtype of Breast Cancer by Analysis of The Cancer Genome Atlas Database

Purpose

We investigated B-cell lymphoma 2 (BCL2) regulation across DNA, RNA, protein, and methylation status according to molecular subtype of breast cancer using The Cancer Genome Atlas (TCGA) database.

Materials and Methods

We analyzed clinical and biological data on 1,096 breast cancers from the TCGA database. Biological data included reverse phase protein array (RPPA), mRNA sequencing (mRNA-seq), mRNA microarray, methylation, copy number alteration linear, copy number alteration nonlinear, and mutation data.

Results

The luminal A and luminal B subtypes showed upregulated expression of RPPA and mRNAseq and hypomethylation compared to the human epidermal growth factor receptor 2 (HER2) and triple-negative subtypes (all p < 0.001). No mutations were found in any subjects. High mRNA-seq and high RPPA were strongly associated with positive estrogen receptor, positive progesterone receptor (all p < 0.001), and negative HER2 (p < 0.001 and p=0.002, respectively). Correlation analysis revealed a strong positive correlation between protein and mRNA levels and a strong negative correlation between methylation and protein and mRNA levels (all p < 0.001). The high BCL2 group showed superior overall survival compared to the low BCL2 group (p=0.006).

Conclusion

The regulation of BCL2 was mainly associated with methylation across the molecular subtypes of breast cancer, and luminal A and luminal B subtypes showed upregulated expression of BCL2 protein, mRNA, and hypomethylation. Although copy number alteration may have played a minor role, mutation status was not related to BCL2 regulation. Upregulation of BCL2 was associated with superior prognosis than downregulation of BCL2.

Prognostic Influence of BCL2 on Molecular Subtypes of Breast Cancer

Purpose

We aimed to reveal the prognostic influence of B-cell CLL/lymphoma 2 (BCL2) on molecular subtypes of breast cancer.

Methods

We analyzed 9,468 patients with primary breast cancer. We classified molecular subtypes according to the National Comprehensive Cancer Network (NCCN) and St. Gallen guidelines, mainly on the basis of the expression of hormonal receptor (HR), human epidermal growth factor receptor 2 (HER2), and Ki-67.

Results

Regarding NCCN classification, BCL2 was a strong favorable prognostic factor in the HR(+)/HER2(–) subtype (p<0.001) and a marginally significant favorable prognosticator in the HR(+)/HER2(+) subtype (p=0.046). BCL2 had no prognostic impact on HR(–)/HER2(+) and HR(–)/HER2(–) subtypes. In relation to St. Gallen classification, BCL2 was a strong favorable prognosticator in luminal A and luminal B/HER2(–) subtypes (both p<0.001). BCL2 was a marginally significant prognosticator in the luminal B/HER2(+) subtype (p=0.046), and it was not a significant prognosticator in HER2 or triple negative (TN) subtypes. The prognostic effect of BCL2 was proportional to the stage of breast cancer in HR(+)/HER2(–), HR(+)/HER2(+), and HR(–)/HER2(–) subtypes, but not in HR(–)/HER2(+) subtype. BCL2 was not a prognostic factor in TN breast cancer regardless of epidermal growth factor receptor expression.

Conclusion

The prognostic influence of BCL2 was different across molecular subtypes of breast cancer, and it was largely dependent on HR, HER2, Ki-67, and the stage of cancer. BCL2 had a strong favorable prognostic impact only in HR(+)/HER2(–) or luminal A and luminal B/HER2(–) subtypes, particularly in advanced stages. Further investigations are needed to verify the prognostic influence of BCL2 on molecular subtypes of breast cancer and to develop clinical applications for prognostication using BCL2.

BCL2 as a Subtype-Specific Prognostic Marker for Breast Cancer

PURPOSE

B-cell lymphoma 2 (BCL2) is an antiapoptosis protein and an important clinical breast cancer prognostic marker. As the role of BCL2 is dependent on the estrogen receptor (ER) status, this effect might differ according to molecular subtypes. The aim of this study was to evaluate the relationship between the prognostic outcomes and BCL2 expression among the molecular subtypes.

METHODS

We retrieved the data of 1,356 patients who were newly diagnosed with malignant breast cancer between November 2006 and November 2011. Immunohistochemistry was used to measure ER, progesterone receptor, human epidermal growth factor receptor 2 (HER2), Ki-67, and BCL2 expression. We classified breast cancer into five molecular subtypes based on the 13th St. Gallen International Expert Consensus, including luminal A, luminal B (HER2-negative), luminal B (HER2-positive), HER2-overexpression, and triple-negative subtypes. We analyzed the clinicopathological features and assessed the correlation between BCL2 expression and clinical outcomes, such as relapse-free survival (RFS) and disease-specific survival (DSS) according to the five molecular subtypes.

RESULTS

A total of 605 cases of breast cancer (53.8%) showed BCL2 expression. BCL2-positive expression was associated with young age (<50 years, p=0.036), lower histological grade (p<0.001), low Ki-67 level (<14%, p<0.001), hormone receptor positivity (p<0.001), HER2 negativity (p<0.001), luminal breast cancer (p<0.001), and low recurrence rate (p=0.016). BCL2-positive expression was also associated with favorable 5-year RFS (p=0.008, 91.4%) and DSS (p=0.036, 95.6%) in all the patients. BCL2-positive expression in luminal A breast cancer resulted in significantly favorable 5-year RFS and DSS (p=0.023 and p=0.041, respectively). However, BCL2 expression was not associated with the prognosis in the other subtypes.

CONCLUSION

The prognostic role of BCL2 expression in breast cancer is subtype-specific. BCL2 expression differs according to the molecular subtype and is a good prognostic marker for only luminal A breast cancer.

Ki-67 is overexpressed in human laryngeal carcinoma and contributes to the proliferation of HEp2 cells

Ki-67 is one of the most useful markers to evaluate cell proliferative activity and has been widely used in tumor treatment and research. However, its role in human laryngeal carcinoma remains poorly defined. The aim of the present study was to investigate the expression of Ki-67 in human laryngeal squamous carcinoma and the effect of Ki-67 gene silencing by small interfering (si)RNA on the proliferation of human laryngocarcinoma HEp2 cells. Immunohistochemistry and reverse transcription-quantitative polymerase chain reaction were performed to examine the expression of Ki-67 in human laryngeal squamous carcinoma tissues and adjacent non-cancer tissues from 50 patients with laryngeal squamous carcinoma. RNA interference was used to knock down the expression of Ki-67 in the HEp2 cell line, and the proliferation of the treated cells was observed in vitro. Western blot analysis was used to determine the expression levels of epidermal growth factor receptor (EGFR) and E-cadherin in the treated cells. The expression of Ki-67 in the laryngeal squamous carcinoma tissues was significantly higher than that of the adjacent non-tumor tissues (P=0.028). The high expression of Ki-67 in cancer was significantly correlated with cervical lymph node metastasis and clinical outcomes (all P<0.001). The silencing of Ki-67 resulted in the inhibition of proliferation of the HEp2 human laryngocarcinoma cells (P<0.001). In addition, compared with the control group, the expression levels of EGFR and E-cadherin in the Ki-67 siRNA-treated cells were significantly decreased (P<0.001) and increased (P<0.001), respectively. These results suggested that Ki-67 is important in regulating the proliferation of human laryngocarcinoma HEp2 cells and that the mechanism may at least partially be associated with the upregulation of EGFR and the downregulation of E-cadherin. Overall, Ki-67 can be used as an important indicator for judging clinical progress and estimating prognosis in human laryngeal squamous carcinoma.

The Contrasting Role of p16Ink4A Patterns of Expression in Neuroendocrine and Non-Neuroendocrine Lung Tumors: A Comprehensive Analysis with Clinicopathologic and Molecular Correlations

Lung cancer encompasses a constellation of malignancies with no validated prognostic markers. p16Ink4A expression has been reported in different subtypes of lung cancers; however, its prognostic value is controversial. Here, we sought to investigate the clinical significance of p16Ink4A immunoexpression according to specific staining patterns and its operational implications. A total of 502 tumors, including 277 adenocarcinomas, 84 squamous cell carcinomas, 22 large cell carcinomas, 47 typical carcinoids, 12 atypical carcinoids, 28 large cell neuroendocrine carcinomas, and 32 small cell carcinomas were reviewed and subjected to immunohistochemical analysis for p16Ink4A and Ki67. The spectrum of p16Ink4A expression was annotated for each case as negative, sporadic, focal, or diffuse. Expression at immunohistochemical level showed intra-tumor homogeneity, regardless tumor histotype. Enrichments in cells expressing p16Ink4A were observed from lower- to higher-grade neuroendocrine malignancies, whereas a decrease was seen in poorly and undifferentiated non-neuroendocrine carcinomas. Tumor proliferation indices were higher in neuroendocrine tumors expressing p16Ink4A while non-neuroendocrine malignancies immunoreactive for p16Ink4A showed a decrease in Ki67-positive cells. Quantitative statistical analyses including each histotype and the p16Ink4A status confirmed the independent prognostic role of p16Ink4A expression, being a high-risk indicator in neuroendocrine tumors and a marker of good prognosis in non-neuroendocrine lung malignancies. In this study, we provide circumstantial evidence to suggest that the routinary assessment of p16Ink4A expression using a three-tiered scoring algorithm, even in a small biopsy, may constitute a reliable, reproducible, and cost-effective substrate for a more accurate risk stratification of each individual patient.

High Bak Expression Is Associated with a Favorable Prognosis in Breast Cancer and Sensitizes Breast Cancer Cells to Paclitaxel

Breast cancer has become the leading cause of cancer-related death among women. A large number of patients become resistant to drug chemotherapy. Paclitaxel (Taxol) is an effective chemotherapeutic agent used to treat cancer patients. Taxol has been widely used in human malignancies including breast cancer because it can stabilize microtubules resulting in cell death by causing an arrest during the G2/M phase of the cell cycle. Pro-apoptotic Bcl-2 antagonist killer 1 (Bak) plays an important role in Taxol-induced apoptosis in breast cancer. In our present study, we investigated the expression of the Bak protein and clinicopathological correlations in a large sample of breast cancer tissues by immunohistochemistry. We found that the percentage of high scores of Bak expression in breast cancer was significantly lower than that of the non-cancerous breast control tissue. In addition, lower Bak expression was positively associated with the clinical TNM stage of breast cancer with a significant decrease in overall survival compared with those with higher Bak expression especially in the Luminal and HER2 subtypes. Importantly, higher Bak expression predicted a favorable clinical outcome in the cases treated with Taxol indicated by a higher overall survival than that of patients with lower Bak expression especially in Luminal and HER2 subtypes. Furthermore, these results were confirmed in vitro since overexpression of Bak sensitized breast cancer cells to Taxol by inhibiting proliferation and promoting apoptosis; in contrast, downregulation of Bak through siRNA transfection inhibited Taxol induced-apoptosis. Therefore, our results demonstrate that Bak acts as a sensitive biomarker and favorable prognostic factor for Taxol treatment in breast cancer. The restoration of Bak expression would be therapeutically beneficial for Taxol resistant breast cancer patients.