Hepatocellular carcinoma-related cyclin D1 is selectively regulated by autophagy degradation system

Dysfunction of degradation machineries causes cancers, including hepatocellular carcinoma (HCC). Overexpression of cyclin D1 in HCC has been reported. We previously reported that autophagy preferentially recruits and degrades the oncogenic microRNA (miR)-224 to prevent HCC. Therefore, in the present study, we attempted to clarify whether cyclin D1 is another oncogenic factor selectively regulated by autophagy in HCC tumorigenesis. Initially, we found an inverse correlation between low autophagic activity and high cyclin D1 expression in tumors of 147 HCC patients and three murine models, and these results taken together revealed a correlation with poor overall survival of HCC patients, indicating the importance of these two events in HCC development. We found that increased autophagic activity leads to cyclin D1 ubiquitination and selective recruitment to the autophagosome (AP) mediated by a specific receptor, sequestosome 1 (SQSTM1), followed by fusion with lysosome and degradation. Autophagy-selective degradation of ubiquitinated cyclin D1 through SQSTM1 was confirmed using cyclin D1/ubiquitin binding site (K_33-238 R) and phosphorylation site (T286A) mutants, lentivirus-mediated silencing autophagy-related 5 (ATG5), autophagy-related 7 (ATG7), and Sqstm1 knockout cells. Functional studies revealed that autophagy-selective degradation of cyclin D1 plays suppressive roles in cell proliferation, colony, and liver tumor formation. Notably, an increase of autophagic activity by pharmacological inducers (amiodarone and rapamycin) significantly suppressed tumor growth in both the orthotopic liver tumor and subcutaneous tumor xenograft models. Our findings provide evidence of the underlying mechanism involved in the regulation of cyclin D1 by selective autophagy to prevent tumor formation.

CONCLUSION

Taken together, our data demonstrate that autophagic degradation machinery and the cell-cycle regulator, cyclin D1, are linked to HCC tumorigenesis. We believe these findings may be of value in the development of alternative therapeutics for HCC patients. (Hepatology 2018;68:141-154).

Liver regeneration accelerates hepatitis B virus-related tumorigenesis of hepatocellular carcinoma

Although partial hepatectomy (PH) to remove tumors provides a potential cure of hepatocellular carcinoma (HCC), long-term survival of hepatitis B virus (HBV)-related HCC patients after PH remains a big challenge. Early recurrence within 2 years post-PH is associated with the dissemination of primary HCC. However, late recurrence after 2 years post-PH is supposed due to the de novo or a secondary tumor. Since PH initiates liver regeneration (LR), we hypothesize that LR may accelerate tumorigenesis through activation of pre-existing precancerous lesions in the remaining liver. In this study, we explored the potential role of several LR-related factors in the de novo recurrence in a HBV X protein (HBx) transgenic mouse model receiving PH to mimic human HCC development. Following PH, we observed that tumor development was significantly accelerated from 16.9 to 10.4 months in HBx transgenic mice. The expression of suppressor of cytokine signaling (SOCS) family proteins was remarkably suppressed in livers of HBx transgenic relative to non-transgenic mice from early to late stages after PH as compared with non-PH mice. The expression of transforming growth factor-β (TGF-β)/Smad pathway, hepatocyte growth factor (HGF), Myc, signal transducer and activator of transcription 3 (STAT3), and β-Catenin also showed a significant difference between livers of HBx transgenic and non-transgenic mice at variable time points after PH in comparison with non-PH mice. Taken together, our results provide an explanation for the high de novo recurrence of HBV-related HCC after PH, probably through induction of the sequential changes of LR-related SOCS family proteins, growth factors, and transcription factors, which may promote growth on the precancerous remnant liver.

Prevalence and Risk Factors for Insomnia in Breast Cancer Survivors Receiving Aromatase Inhibitors

Purpose: Insomnia is increasingly recognized as a major symptom outcome in oncology; however, its prevalence and risk factors have not been previously defined in women receiving aromatase inhibitors (AI) for breast cancer.Patients and Methods: We performed a cross-sectional analysis of a cohort of postmenopausal women with stage 0-III breast cancer receiving adjuvant AI therapy at an outpatient breast oncology clinic at a large university hospital. The validated Insomnia Severity Index (ISI) was the primary outcome (Cronbach's alpha of 0.91 in this population). According to ISI, Insomnia was categorized as: no clinically significant insomnia, 0-7; sub-threshold insomnia 8-14; clinical insomnia (moderate severity), 15-12; clinical insomnia (severe), 22-28. We defined anyone who had clinical insomnia with a score of 15 or above. Multivariate logistic regression analyses were performed to assess risk factor(s).Results: 367 patients have been analyzed, with a mean age of 61.6 +/- 10 years. 83.6% were White and 12.9% Black. While 124 (34.1%) had sub-threshold insomnia, 67 (18.4%) met criteria for clinical insomnia based on ISI: 58 (15.9%) for clinically moderate insomnia and 9 (2.5%) clinically severe insomnia. Of the entire sample, 31% considered seeking treatment for insomnia over the previous month. In a multivariate logistic regression model, clinical insomnia was independently associated with current joint pain (odds ratio [OR], 4.41, 95% confidence interval [CI], 2.17-8.96, p<0.001) and hot flashes (OR, 3.00, 95% CI, 1.58-5.71, p=0.001). While education level (college only vs. graduate or professional degree) was also associated with increased risk for clinical insomnia (OR, 2.46, 95% CI, 1.18-5.14, p=0.016), no other demographic, clinical or treatment variable was related to clinical insomnia.Conclusions: Insomnia is a substantial problem among breast cancer survivors receiving aromatase inhibitors and is highly associated with joint pain and hot flashes. Thus, effective treatment of joint pain and hot flashes may help improve insomnia in this population.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1062.

Relationships between clinical and biochemical predictors of chemotherapy-related amenorrhea in premenopausal adjuvant breast cancer patients

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Background: Premature ovarian failure (POF) is a major side effect of breast cancer adjuvant therapy. Predicting post- chemotherapy POF and reproductive status impacts decisions about fertility, contraception, menopausal issues and breast cancer treatment. We examined clinical and biochemical predictors of chemotherapy related amenorrhea (CRA) in premenopausal adjuvant breast cancer patients. Methods: We conducted a cohort study of 121 breast cancer patients with stages I-III disease, premenopausal at diagnosis, enrolled 1 to 4 years from chemotherapy. All patients received 4 cycles of doxorubicin and cyclophosphomide with or without 4 cycles of paclitaxel or docetaxel, at q2 (dose-dense) or q3 week intervals. The primary endpoint was CRA (amenorrhea > 12 months from chemotherapy start). Pretreatment menstrual status and clinical factors were collected prospectively; subjects were recontacted for additional information and venipuncture. Regression models were used to examine risk factors for CRA and log FSH. Results: Mean age was 43.2 years (range 26.7–57.8). Mean follow up from chemotherapy start to enrollment was 2.1 years (range 1.0–4.1). 68 subjects developed CRA, while 53 continued menstruating. In a model including age, tamoxifen use, dose density, chemotherapy regimen, ovarian suppression during chemotherapy, smoking, body mass index and race, only age (OR 1.57[CI 1.29–1.89], p<0.001), tamoxifen use (OR 7.25 [CI 5.89–34.87], p=0.01), and dose density (OR 3.38 [CI 1.16–16.50], p=0.03) had independent associations with CRA. Serum FSH at enrollment (n=112) was higher in CRA than in non-CRA (11.8 vs 45.8, p< 0.001). However, 39% (25/65) of CRA subjects had FSH < 40 mIU/mL, the biochemical threshold for menopause (mean 26.4, range 10.1–39.9). FSH was not associated with chemotherapy regimen (p=0.51) or schedule (p=0.21). Conclusions: Age, tamoxifen use, dose density and subsequent FSH were independently associated with CRA. Clinically, amenorrhea for more than 12 months did not always represent biochemical menopause. Better methods are needed to characterize ovarian function in patients after adjuvant chemotherapy.

No significant financial relationships to disclose.

An interferon-gamma-related cytokine storm in SARS patients

Fourteen cytokines or chemokines were analyzed on 88 RT-PCR-confirmed severe acute respiratory syndrome (SARS) patients. IFN-gamma, IL-18, TGF-beta, IL-6, IP-10, MCP-1, MIG, and IL-8, but not of TNF-alpha, IL-2, IL-4, IL-10, IL-13, or TNFRI, were highly elevated in the acute phase sera of Taiwan SARS patients. IFN-gamma was significantly higher in the Ab(+) group than in the Ab(-) group. IFN-gamma, IL-18, MCP-1, MIG, and IP-10 were already elevated at early days post fever onset. Furthermore, levels of IL-18, IP-10, MIG, and MCP-1 were significantly higher in the death group than in the survival group. For the survival group, IFN-gamma and MCP-1 were inversely associated with circulating lymphocytes count and monocytes count, but positively associated with circulating neutrophils count. It is concluded that an interferon-gamma-related cytokine storm was induced post SARS coronavirus infection, and this cytokine storm might be involved in the immunopathological damage in SARS patients.

Evaluation of antibody responses against SARS coronaviral nucleocapsid or spike proteins by immunoblotting or ELISA

Severe acute respiratory syndrome (SARS)-CoV is a newly emerging virus that causes SARS with high mortality rate in infected people. To study the humoral responses against SARS-CoV, we evaluated nucleocapsid (N) and spike (S) proteins-specific antibodies in patients' sera by Western blotting and enzyme-linked immunosorbent assay (ELISA). Recombinant N and S proteins of SARS-CoV were purified from transformed E. coli. Serum specimens from 40 SARS-CoV-infected patients in the convalescent phase were analyzed by Western blotting using the purified antigens. Serial serum specimens from 12 RT-PCR-confirmed SARS patients were assayed by ELISA using the recombinant N protein as coated antigen. By Western blotting, 97.5% of the SARS patients were positive for N protein-specific antibodies whereas only 47.5% of the samples were positive for S protein-specific antibodies. Using N protein-based ELISA, 10 out of the 12 patients were positive for N protein-specific antibodies and 6 of them showed seroconversion at mean of 16 days after onset of fever. Immunoblotting was useful for detecting the humoral immune response after SARS-CoV infection. Antibodies against SARS-CoV N protein appear at the early stage of infection, therefore, N protein-based ELISA could serve as a simple, sensitive, and specific test for diagnosing SARS-CoV infection.

B-1 cells: orthodox or conformist?

B-1 cells differ from conventional peripheral B cells (B-2) by anatomical location, surface marker expression, antibody repertoire and growth properties. The lineage hypothesis of B-1 cell development attributes the properties of B-1 cells to their unique origin. The induced differentiation hypothesis suggests the surface-immunoglobulin-driven development of B-1 cells from common B-1/B-2 cell progenitors. In both models self-antigen-induced signalling plays the central role in positive selection of B-1 cells. The ability of B-1 cells to be positively selected by self-antigens raises questions about the mechanism of this phenomenon.

The molecular mechanism of B cell activation by toll-like receptor protein RP-105

The B cell-specific transmembrane protein RP-105 belongs to the family of Drosophila toll-like proteins which are likely to trigger innate immune responses in mice and man. Here we demonstrate that the Src-family protein tyrosine kinase Lyn, protein kinase C beta I/II (PKCbetaI/II), and Erk2-specific mitogen-activated protein (MAP) kinase kinase (MEK) are essential and probably functionally connected elements of the RP-105-mediated signaling cascade in B cells. We also find that negative regulation of RP-105-mediated activation of MAP kinases by membrane immunoglobulin may account for the phenomenon of antigen receptor-mediated arrest of RP-105-mediated B cell proliferation.

Modulation of retinoic Acid receptor-alpha, growth-factors and protooncogenes in retinoic Acid-induced apoptosis of ki-1 lymphoma cell-line

We have previously reported the successful salvage by retinoid acid (RA) of patients with refractory Ki-1 lymphoma. In this study, we have further investigated the effect of all-trans RA on a Ki-1 lymphoma cell line SR786. Similar to the clinical observation, SR786 cells were sensitive to RA treatment (ID50=0.6 mu m). RA-treated SR786 cells were transformed to a more differentiated morphology at 24 h, and subsequently died via apoptosis at 48-72 h. This process was associated with a decreased expression of the proliferation markers and c-myc proto-oncogene. The RA receptor alpha (RAR-alpha), however, showed an immediate enhanced expression at 1/2 h, and followed by an increase of transforming growth factor-beta 1 (TGF-beta 1) gene expression. The apoptosis and increased expression of TGF-beta 1 could be completely blocked;by the addition of cycloheximide given within 12 h of RA treatment. It appears that the RA-induced apoptosis of SR-786 is the result of an RA-induced upregulation of RAR-alpha and a subsequent activation of TGF-beta 1, which in turn leads to a cascade of the suppression of growth-related genes. Our observations strongly support the use of retinoids in Ki-1 lymphoma and invite further studies to test the potential of RA in other specific type T-cell lymphomas.

Elimination of PBBs in rats. Effect of mineral oil and/or feed restriction

Rats were fed polybrominated biphenyls (PBBs) at 0.1 to 100.0 ppm for 14 d and then treated to hasten the removal of PBBs with 0, 5, or 10% mineral oil (MO) and/or 0, 15, 30, or 45% feed restriction (FR) for 21 d. PBB body burdens were determined at d 14 and expressed on a log-log basis by Y = 0.91X + 2.179 (r2 = 0.974), where X = log of PBB concentration in diet (ppm) and Y = log of PBB body burden (micrograms). After 21 d withdrawal, body burdens were expressed by the equation Y = 0.787X + 2.218 (r2 = 0.95). The most effective withdrawal treatment was 10% MO + 45% FR producing a reduction of body burdens inversely related to prior body burdens (69% at 0.1 ppm to 23% at 100 ppm). Body weights and fat content were significantly (p less than or equal to .05) reduced by feed restriction, with fat content only 39% of controls at 21 d off. Mortality averaged 0, 13.6, and 35.8% for rats fed 0, 5, or 10% MO, and 25, 15, 8.6, and 3.7% for rats feed restricted at 0, 15, 30, and 45%, respectively. Histopathology of the dead and moribund rats indicated that the clinical signs were not characteristic of PBB toxicity. In a second experiment, safflower oil at 3.5% or excess vitamins prevented the mortality and clinical signs associated with MO during withdrawal from 100 ppm PBBs. Based on these data and those in the literature, PBBs interfere with vitamin utilization.