Deep feature extraction and fine κ-nearest neighbour for enhanced human papillomavirus detection in cervical cancer - a comprehensive analysis of colposcopy images.

Introduction: This study introduces a novel methodology for classifying human papillomavirus (HPV) using colposcopy images, focusing on its potential in diagnosing cervical cancer, the second most prevalent malignancy among women globally. Addressing a crucial gap in the literature, this study highlights the unexplored territory of HPV-based colposcopy image diagnosis for cervical cancer. Emphasising the suitability of colposcopy screening in underdeveloped and low-income regions owing to its small, cost-effective setup that eliminates the need for biopsy specimens, the methodological framework includes robust dataset augmentation and feature extraction using EfficientNetB0 architecture. Material and methods: The optimal convolutional neural network model was selected through experimentation with 19 architectures, and fine-tuning with the fine κ-nearest neighbour algorithm enhanced the classification precision, enabling detailed distinctions with a single neighbour. Results: The proposed methodology achieved outstanding results, with a validation accuracy of 99.9% and an area under the curve (AUC) of 99.86%, with robust performance on test data, 91.4% accuracy, and an AUC of 91.76%. These remarkable findings underscore the effectiveness of the integrated approach, which offers a highly accurate and reliable system for HPV classification.Conclusions: This research sets the stage for advancements in medical imaging applications, prompting future refinement and validation in diverse clinical settings.

Targeting ER stress/PKA/GSK-3ß/ß-catenin pathway as a potential novel strategy for hepatitis C virus-infected patients.

BACKGROUND: Chronic hepatitis C virus (HCV) infection causes hepatocellular carcinoma (HCC). The HCC risk, while decreased compared with active HCV infection, persists in HCV-cured patients by direct-acting antiviral agents (DAA). We previously demonstrated that Wnt/ß-catenin signaling remained activated after DAA-mediated HCV eradication. Developing therapeutic strategies to both eradicate HCV and reverse Wnt/ß-catenin signaling is needed. METHODS: Cell-based HCV long term infection was established. Chronically HCV infected cells were treated with DAA, protein kinase A (PKA) inhibitor H89 and endoplasmic reticulum (ER) stress inhibitor tauroursodeoxycholic acid (TUDCA). Western blotting analysis and fluorescence microscopy were performed to determine HCV levels and component levels involved in ER stress/PKA/glycogen synthase kinase-3ß (GSK-3ß)/ß-catenin pathway. Meanwhile, the effects of H89 and TUDCA were determined on HCV infection. RESULTS: Both chronic HCV infection and replicon-induced Wnt/ß-catenin signaling remained activated after HCV and replicon eradication by DAA. HCV infection activated PKA activity and PKA/GSK-3ß-mediated Wnt/ß-catenin signaling. Inhibition of PKA with H89 both repressed HCV and replicon replication and reversed PKA/GSK-3ß-mediated Wnt/ß-catenin signaling in both chronic HCV infection and replicon. Both chronic HCV infection and replicon induced ER stress. Inhibition of ER stress with TUDCA both repressed HCV and replicon replication and reversed ER stress/PKA/GSK-3ß-dependent Wnt/ß-catenin signaling. Inhibition of either PKA or ER stress both inhibited extracellular HCV infection. CONCLUSION: Targeting ER stress/PKA/GSK-3ß-dependent Wnt/ß-catenin signaling with PKA inhibitor could be a novel therapeutic strategy for HCV-infected patients to overcomes the issue of remaining activated Wnt/ß-catenin signaling by DAA treatment. Video Abstract.

Integrated stress response in hepatitis C promotes Nrf2-related chaperone-mediated autophagy: A novel mechanism for host-microbe survival and HCC development in liver cirrhosis.

The molecular mechanism(s) how liver damage during the chronic hepatitis C virus (HCV) infection evolve into cirrhosis and hepatocellular carcinoma (HCC) is unclear. HCV infects hepatocyte, the major cell types in the liver. During infection, large amounts of viral proteins and RNA replication intermediates accumulate in the endoplasmic reticulum (ER) of the infected hepatocyte, which creates a substantial amount of stress response. Infected hepatocyte activates a different type of stress adaptive mechanisms such as unfolded protein response (UPR), antioxidant response (AR), and the integrated stress response (ISR) to promote virus-host cell survival. The hepatic stress is also amplified by another layer of innate and inflammatory response associated with cellular sensing of virus infection through the production of interferon (IFN) and inflammatory cytokines. The interplay between various types of cellular stress signal leads to different forms of cell death such as apoptosis, necrosis, and autophagy depending on the intensity of the stress and nature of the adaptive cellular response. How do the adaptive cellular responses decode such death programs that promote host-microbe survival leading to the establishment of chronic liver disease? In this review, we discuss how the adaptive cellular response through the Nrf2 pathway that promotes virus and cell survival. Furthermore, we provide a glimpse of novel stress-induced Nrf2 mediated compensatory autophagy mechanisms in virus-cell survival that degrade tumor suppressor gene and activation of oncogenic signaling during HCV infection. Based on these facts, we hypothesize that the balance between hepatic stress, inflammation and different types of cell death determines liver disease progression outcomes. We propose that a more nuanced understanding of virus-host interactions under excessive cellular stress may provide an answer to the fundamental questions why some individuals with chronic HCV infection remain at risk of developing cirrhosis, cancer and some do not.

Yes-Associated Protein in Kupffer Cells Enhances the Production of Proinflammatory Cytokines and Promotes the Development of Nonalcoholic Steatohepatitis.

BACKGROUND AND AIMS: Yes-associated protein (YAP) plays an important role in hepatocarcinogenesis, although the potential role of YAP in non-neoplastic liver diseases remains largely unknown. We report herein that YAP in Kupffer cells (KCs) enhances the production of proinflammatory cytokines and promotes the development of nonalcoholic steatohepatitis (NASH). Our data show that the expression of YAP is significantly increased in KCs of wild-type mice fed a high-fat diet (HFD). APPROACH AND RESULTS: We generated mice with macrophage/monocyte-specific deletion of YAP (YAPϕKO ) or Toll-like receptor 4 (TLR4; TLR4ϕKO ), and animals were fed an HFD or treated with lipopolysaccharide (LPS). Our data showed that YAPϕKO mice fed an HFD exhibited lower serum alanine aminotransferase (ALT)/aspartate aminotransferase (AST) levels and less hepatic inflammation when compared to their littermate controls. LPS treatment induced accumulation of YAP in KCs in vitro and in mice, which was prevented by macrophage/monocyte-specific deletion of TLR4 (TLR4ϕKO ). LPS transcriptionally activates YAP through activator protein 1 in macrophages/KCs. LPS-induced YAP further enhances expression of proinflammatory cytokines (including monocyte chemoattractant protein 1, tumor necrosis factor alpha, and interleukin 6) through YAP association with the TEA domain-binding motif in the promoter region of inflammatory cytokines. Forced overexpression of active YAP (YAP5SA) in KCs enhanced the production of proinflammatory cytokines. Treatment of HFD-fed mice with verteporfin inhibited KC activation, reduced liver inflammation, and decreased serum ALT/AST levels. Analyses of liver tissues from NASH patients reveal that YAP is increased in KCs and that level of YAP in human liver tissues is positively correlated with expression of proinflammatory cytokines. CONCLUSIONS: This study describes an important role of YAP in KCs for regulation of liver inflammation in NASH. Our findings suggest that inhibition of YAP may represent an effective therapeutic strategy for NASH treatment.

Targeted Delivery of Doxorubicin Liposomes for Her-2+ Breast Cancer Treatment.

The adverse side effects and toxicity caused by the non-targeted delivery of doxorubicin has emphasized the demand of emerging a targeted delivery system. The goal of this study is to enhance the delivery of doxorubicin by formulating an aptamer-labeled liposomal nanoparticle delivery system that will carry and deliver doxorubicin specifically into Her-2+ breast cancer cells. Twelve liposomal batches were prepared using different saturated (HSPC and DPPC) and unsaturated (POPC and DOPC) lipids by thin film hydration. The liposomes were characterized for their particle size, zeta potential, and drug encapsulation efficiency. The particles were also assessed for in vitro toxicity and DOX delivery into the breast cancer cells. The formulations, F1 through F12, had a small particle size of less than 200 nm and a high entrapment efficiency of about 88 ± 5%. The best formulation, F5, had a particle size of 101 ± 14nm, zeta potential of + 5.63 ± 0.46 mV, and entrapment efficiency of ≈ 93%. The cytotoxicity studies show that the DOX-loaded liposomal formulations are more effective in killing cancer cells than the free DOX in both MCF-7 and SKBR-3 cells. The uptake studies show a significant increase in the uptake of the aptamer-labeled liposomes (i.e., F5) by more than 60% into Her-2+ MCF-7 and SKBR-3 breast cancer cells compare to non-aptamer-labeled nanoparticles. F5 also shows ≈ 1.79-fold increase in uptake of DOX in the Her-2+ cells compared to the Her-2- cells. This preliminary study indicates that aptamer-labeled F5 nanoparticles among several batches showed the highest uptake as well as the targeted delivery of doxorubicin into Her-2+ breast cancer cells. Thus, aptamer targeted approach results in substantial reduction in the dose of DOX and improves the therapeutic benefits by promoting the target specificity.

Adult Hepatocytes Are Hedgehog-Responsive Cells in the Setting of Liver Injury: Evidence for Smoothened-Mediated Activation of NF-κB/Epidermal Growth Factor Receptor/Akt in Hepatocytes that Counteract Fas-Induced Apoptosis.

Although hedgehog (Hh) signaling pathway is inactive in adult healthy liver, it becomes activated during acute and chronic liver injury and, thus, modulates the reparative process and disease progression. We developed a novel mouse model with liver-specific knockout of Smoothened (Smo LKO), and animals were subjected to Fas-induced liver injury in vivo. Results showed that Smo deletion in hepatocytes enhances Fas-induced liver injury. Activation of Hh signaling in hepatocytes in the setting of Fas-induced injury was indicated by the fact that Jo2 treatment enhanced hepatic expression of Ptch1, Smo, and its downstream target Gli1 in control but not Smo LKO mice. Primary hepatocytes from control mice showed increased Hh signaling activation in response to Jo2 treatment in vitro. On the other hand, the Smo KO hepatocytes were devoid of Hh activation and were more susceptible to Jo2-induced apoptosis. The levels of NF-κB and related signaling molecules, including epidermal growth factor receptor and Akt, were lower in Smo KO livers/hepatocytes than in control livers/hepatocytes. Accordingly, hydrodynamic gene delivery of active NK-κB prevented Jo2-induced liver injury in the Smo LKO mice. Our findings provide important evidence that adult hepatocytes become responsive to Hh signaling through up-regulation of Smo in the setting of Fas-induced liver injury and that such alteration leads to activation of NF-κB/epidermal growth factor receptor/Akt, which counteracts Fas-induced hepatocyte apoptosis.

Chaperone-Mediated Autophagy Promotes Beclin1 Degradation in Persistently Infected Hepatitis C Virus Cell Culture.

Liver cirrhosis is an independent risk factor for hepatocellular carcinoma (HCC). The mechanisms that contribute to HCC development in the cirrhotic microenvironment are unknown. We found that HCC grown in the highly stressed cirrhotic microenvironment undergoes autophagy switching from a protective state characterized by high macroautophagy with low chaperone-mediated autophagy (CMA) to an HCC-promoting state characterized by low macroautophagy with high CMA. This study examined how the stress response executes oncogenic cell programming through autophagy switching using hepatitis C virus cell culture. Protein kinase R-like endoplasmic reticulum kinase expression increased to high levels in hepatitis C virus culture. Protein kinase R-like endoplasmic reticulum kinase-dependent activation of nuclear factor erythroid 2-related factor (Nrf2) led to increased transcription of the cytoprotective genes: heat shock cognate 70 kDa protein and lysosome-associated membrane protein 2A (LAMP2A) and precipitated the induction of CMA. CMA selectively targeted beclin1 degradation, leading to accumulation of the autophagy flux protein p62 due to impaired autophagosome-endosome fusion. This impaired autophagosome-endosome fusion due to beclin1 degradation inhibited endocytosis and degradation of epidermal growth factor receptor. Silencing Nrf2 and LAMP2A reduced cell viability, suggesting that the stress response activates CMA as a compensatory mechanism of cell survival. We report a novel mechanism through which stress response triggers oncogenic Nrf2 signaling that promotes autophagy switching to favor cell survival.

Amphiphilic Polypeptoids Rupture Vesicle Bilayers To Form Peptoid-Lipid Fragments Effective in Enhancing Hydrophobic Drug Delivery.

Peptoids are highly biocompatible pseudopeptidic polyglycines with designable substituents on the nitrogen atoms. The therapeutic and drug-carrying potential of these materials requires a fundamental understanding of their interactions with lipid bilayers. In this work, we use amphiphilic polypeptoids with up to 100 monomeric units where a significant fraction (26%) of the nitrogen atoms are functionalized with decyl groups (hydrophobes) that insert into the lipid bilayer through the hydrophobic effect. These hydrophobically modified polypeptoids (HMPs) insert their hydrophobes into lipid bilayers creating instabilities that lead to the rupture of vesicles. At low HMP concentrations, such rupture leads to the creation of large fragments which remarkably anchor to intact vesicles through the hydrophobic effect. At high HMP concentrations, all vesicles rupture to smaller HMP-lipid fragments of the order of 10 nm. We show that the technique for such nanoscale polymer-lipid fragments can be exploited to sustain highly hydrophobic drug species in solution. Using the kinase inhibitor, Sorafenib as a model drug, it is shown that HMP-lipid fragments containing the drug can efficiently enter a hepatocellular carcinoma cell line (Huh 7.5), indicating the use of such fragments as drug delivery nanocarriers.

Cellular Mechanism for Impaired Hepatitis C Virus Clearance by Interferon Associated with IFNL3 Gene Polymorphisms Relates to Intrahepatic Interferon-λ Expression.

The single nucleotide polymorphism located within the IFNL3 (also known as IL28B) promoter is one of the host factors associated with hepatitis C virus (HCV) clearance by interferon (IFN)-α therapy; however the mechanism remains unknown. We investigated how IL28B gene polymorphism influences HCV clearance with infected primary human hepatocytes, liver biopsies, and hepatoma cell lines. Our study confirms that the rs12979860-T/T genotype has a strong correlation with ss469415590-ΔG/ΔG single nucleotide polymorphism that produces IFN-λ4 protein. We found that IFN-α and IFN-λ1 antiviral activity against HCV was impaired in IL28B T/T infected hepatocytes compared with C/C genotype. Western blot analysis showed that IL28B TT genotype hepatocytes expressed higher levels of IFN-λ proteins (IL28B, IL-29), preactivated IFN-stimulated gene (ISG) expression, and impaired Stat phosphorylation when stimulated with either IFN-α or IFN-λ1. Furthermore, we showed that silencing IFN-λ1 in T/T cell line reduced basal ISG expression and improved antiviral activity. Likewise, overexpression of IFN-λ (1 to 4) in C/C cells induced basal ISG expression and prevented IFN-α antiviral activity. We showed that IFN-λ4, produced at low level only in T/T cells induced expression of IL28B and IL-29 and prevented IFN-α antiviral activity in HCV cell culture. Our results suggest that IFN-λ4 protein expression associated with the IL28B-T/T variant preactivates the Janus kinase-Stat signaling, leading to impaired HCV clearance by both IFN-α and IFN-λ.

Inhibition of hedgehog signaling ameliorates hepatic inflammation in mice with nonalcoholic fatty liver disease.

UNLABELLED: Hedgehog (Hh) signaling plays a critical role in liver development, regeneration, injury repair, and carcinogenesis. Activation of Hh signaling has been observed in patients with nonalcoholic fatty liver diseases (NAFLD); however, the pathobiological function and regulatory mechanism of hepatic Hh signaling in the pathogenesis of NAFLD remain to be further defined. This study was designed to examine the effect and mechanism of hepatic Hh signaling in high-fat diet-induced NAFLD by using pharmacological Smoothened (Smo) inhibitors (GDC-0449 and LED225) and liver-specific Smo knockout mice. Administration of Smo inhibitors to high-fat diet-fed wild-type mice significantly reduced the numbers of activated macrophages and decreased the expression of proinflammatory cytokines (tumor necrosis factor-α, interleukin-1ß, monocyte chemoattractant protein 1, and interleukin-6) as assessed by F4/80 immunohistochemistry and quantitative reverse-transcription polymerase chain reaction, respectively. The Smo inhibitors were noted to have variable effects on hepatic fat accumulation. Liver-specific deletion of Smo also reduced macrophage activation and inhibited proinflammatory cytokine expression, while it did not significantly alter fat accumulation in the liver. Mechanistically, we found that activation of glioma-associated oncogene 1 by Hh signaling in primary hepatocytes increased the production of osteopontin, which subsequently enhanced the macrophage-mediated proinflammatory response through paracrine signaling. CONCLUSION: Hepatocyte Hh signaling can promote liver inflammation through osteopontin-mediated macrophage activation; this mechanism importantly contributes to the progression of NAFLD.

Persistent hepatitis C virus infection impairs ribavirin antiviral activity through clathrin-mediated trafficking of equilibrative nucleoside transporter 1.

UNLABELLED: Ribavirin (RBV) continues to be an important component of interferon-free hepatitis C treatment regimens, as RBV alone does not inhibit hepatitis C virus (HCV) replication effectively; the reason for this ineffectiveness has not been established. In this study, we investigated the RBV resistance mechanism using a persistently HCV-infected cell culture system. The antiviral activity of RBV against HCV was progressively impaired in the persistently infected culture, whereas interferon lambda 1 (IFN-λ1), a type III IFN, showed a strong antiviral response and induced viral clearance. We found that HCV replication in persistently infected cultures induces an autophagy response that impairs RBV uptake by preventing the expression of equilibrative nucleoside transporter 1 (ENT1). The Huh-7.5 cell line treated with an autophagy inducer, Torin 1, downregulated membrane expression of ENT1 and terminated RBV uptake. In contrast, the autophagy inhibitors hydroxychloroquine (HCQ), 3-methyladenine (3-MA), and bafilomycin A1 (BafA1) prevented ENT1 degradation and enhanced RBV antiviral activity. The HCV-induced autophagy response, as well as treatment with Torin 1, degrades clathrin heavy chain expression in a hepatoma cell line. Reduced expression of the clathrin heavy chain by HCV prevents ENT1 recycling to the plasma membrane and forces ENT1 to the lysosome for degradation. This study provides a potential mechanism for the impairment of RBV antiviral activity in persistently HCV-infected cell cultures and suggests that inhibition of the HCV-induced autophagy response could be used as a strategy for improving RBV antiviral activity against HCV infection. IMPORTANCE: The results from this work will allow a review of the competing theories of antiviral therapy development in the field of HCV virology. Ribavirin (RBV) remains an important component of interferon-free hepatitis C treatment regimens. The reason why RBV alone does not inhibit HCV replication effectively has not been established. This study provides a potential mechanism for why RBV antiviral activity is impaired in persistently HCV-infected cell cultures and suggests that inhibition of the HCV-induced autophagy response could be used as a strategy to increase RBV antiviral activity against HCV infection. Therefore, it is anticipated that this work would generate a great deal of interest, not only among virologists but also among the general public.

Unexpected structural features of the hepatitis C virus envelope protein 2 ectodomain.

Hepatitis C virus (HCV), a member of the family Flaviviridae, is a leading cause of chronic liver disease and cancer. Recent advances in HCV therapeutics have resulted in improved cure rates, but an HCV vaccine is not available and is urgently needed to control the global pandemic. Vaccine development has been hampered by the lack of high-resolution structural information for the two HCV envelope glycoproteins, E1 and E2. Recently, Kong and coworkers (Science 342:1090-1094, 2013, doi:10.1126/science.1243876) and Khan and coworkers (Nature 509[7500]:381-384, 2014, doi:10.1038/nature13117) independently determined the structure of the HCV E2 ectodomain core with some unexpected and informative results. The HCV E2 ectodomain core features a globular architecture with antiparallel ß-sheets forming a central ß sandwich. The residues comprising the epitopes of several neutralizing and nonneutralizing human monoclonal antibodies were also determined, which is an essential step toward obtaining a fine map of the human humoral response to HCV. Also clarified were the regions of E2 that directly bind CD81, an important HCV cellular receptor. While it has been widely assumed that HCV E2 is a class II viral fusion protein (VFP), the newly determined structure suggests that the HCV E2 ectodomain shares structural and functional similarities only with domain III of class II VFPs. The new structural determinations suggest that the HCV glycoproteins use a different mechanism than that used by class II fusion proteins for cell fusion.

HCV infection selectively impairs type I but not type III IFN signaling.

A stable and persistent Hepatitis C virus (HCV) replication cell culture model was developed to examine clearance of viral replication during long-term treatment using interferon-α (IFN-α), IFN-λ, and ribavirin (RBV). Persistently HCV-infected cell culture exhibited an impaired antiviral response to IFN-α+RBV combination treatment, whereas IFN-λ treatment produced a strong and sustained antiviral response that cleared HCV replication. HCV replication in persistently infected cells induced chronic endoplasmic reticulum (ER) stress and an autophagy response that selectively down-regulated the functional IFN-α receptor-1 chain of type I, but not type II (IFN-γ) or type III (IFN-λ) IFN receptors. Down-regulation of IFN-α receptor-1 resulted in defective JAK-STAT signaling, impaired STAT phosphorylation, and impaired nuclear translocation of STAT. Furthermore, HCV replication impaired RBV uptake, because of reduced expression of the nucleoside transporters ENT1 and CNT1. Silencing ER stress and the autophagy response using chemical inhibitors or siRNA additively inhibited HCV replication and induced viral clearance by the IFN-α+RBV combination treatment. These results indicate that HCV induces ER stress and that the autophagy response selectively impairs type I (but not type III) IFN signaling, which explains why IFN-λ (but not IFN-α) produced a sustained antiviral response against HCV. The results also indicate that inhibition of ER stress and of the autophagy response overcomes IFN-α+RBV resistance mechanisms associated with HCV infection.

Epigenetic regulation of MicroRNA-122 by peroxisome proliferator activated receptor-gamma and hepatitis b virus X protein in hepatocellular carcinoma cells.

UNLABELLED: MicroRNA-122 (miR-122), a pivotal liver-specific miRNA, has been implicated in several liver diseases including hepatocellular carcinoma (HCC) and hepatitis C and B viral infection. This study aimed to explore epigenetic regulation of miR-122 in human HCC cells and to examine the effect of hepatitis C virus (HCV) and hepatitis B virus (HBV). We performed microRNA microarray analysis and identified miR-122 as the most up-regulated miRNA (6-fold) in human HCC cells treated with 5'aza-2'deoxycytidine (5-Aza-CdR, DNA methylation inhibitor) and 4-phenylbutyric acid (PBA, histone deacetylation inhibitor). Real-time polymerase chain reaction (PCR) analysis verified significant up-regulation of miR-122 by 5'aza and PBA in HCC cells, and to a lesser extent in primary hepatocytes. Peroxisome proliferator activated receptor-gamma (PPARγ) and retinoid X receptor alpha (RXRα) complex was found to be associated with the DR1 and DR2 consensus site in the miR-122 gene promoter which enhanced miR-122 gene transcription. 5-Aza-CdR and PBA treatment increased the association of PPARγ/RXRα, but decreased the association of its corepressors (N-CoR and SMRT), with the miR-122 DR1 and DR2 motifs. The aforementioned DNA-protein complex also contains SUV39H1, an H3K9 histone methyl transferase, which down-regulates miR-122 expression. CONCLUSIONS: These findings establish a novel role of the PPARγ binding complex for epigenetic regulation of miR-122 in human HCC cells. Moreover, we show that hepatitis B virus X protein binds PPARγ and inhibits the transcription of miR-122, whereas hepatitis C viral particles exhibited no significant effect; these findings provide mechanistic insight into reduction of miR-122 in patients with HBV but not with HCV infection.

Interferon alpha induced intrahepatic pSTAT1 inversely correlate with serum HCV RNA levels in chronic HCV infection.

BACKGROUND: The Jak-STAT signaling of hepatitis C virus (HCV) infected hepatocyte is critical for the antiviral action of endogenously produced interferon (IFN) as well as exogenously administered interferon alpha (IFN-α). The activation of cellular Jak-STAT signaling by IFN-α results in the phosphorylation and nuclear translocation of pSTAT1 and pSTAT2 proteins to induce antiviral gene transcription. Clinical studies show that chronic HCV patients with high viral load show poor response to interferon alpha and ribavirin combination therapy. AIM: We seek to determine whether the IFN-α induced activation of pSTAT1 and pSTAT2 in hepatocytes isolated from liver biopsy of patients chronically infected with hepatitis C virus could be related to the viral load. METHOD: Hepatocytes were isolated from liver biopsies of 18 chronic HCV patients using the collagen digestion method. Induction of pSTAT1 protein in the isolated hepatocyte was measured after IFN-α treatment. The fold change in the levels of pStat1 in the cell lysates due to IFN-treatment was measured by Western blot analysis followed by densitometry analysis. RESULTS: Results of our study indicate that IFN-α induced pSTAT1 levels vary in chronically infected hepatocytes from chronic HCV patients. Semi-quantitative analysis of the pSTAT1 bands revealed a median induction of 7.4-fold in non-infected primary hepatocytes and 2.3-fold in chronic hepatitis C patients (p < 0.001). Total STAT1 levels were not significantly different between treated and untreated primary hepatocytes. We also found a significantly inverse correlation between the intrahepatic pSTAT1 inductions with the serum HCV RNA levels. CONCLUSION: We have developed an antibody based Western blot detection method to measure intrahepatic pStat1 and pStat2 levels to assess the cellular response to exogenous IFN-alpha. Our results indicate that pStat1 activation is a good indicator to assess the level of HCV replication in chronic HCV patients.

Impaired autophagy response in human hepatocellular carcinoma.

BACKGROUND: Autophagy is a cellular lysosomal degradation mechanism that has been implicated in chronic liver diseases and hepatocellular carcinoma (HCC). Association of autophagy defect with the development of human HCC has been shown in transgenic mouse model. AIM: We performed this study to verify whether a defect in autophagy would play a role in human hepatocellular carcinoma (HCC). METHODS: Archival tissue sections of 20 patients with HCC with or without hepatitis C virus (HCV) infection were studied. All slides were immunostained using monoclonal antibodies to p62 and glypican-3 with appropriate positive and negative controls. The expression of p62 and glycican-3 in the HCC and the surrounding non-tumor was semiquantitated. The cytoplasmic staining was graded as negative, weak or strong. RESULTS: Positive p62 staining was found in 20 out of 20 (100%) HCCs and negative staining was observed in 20 out of 20 non-tumor areas and cirrhotic nodules. Positive glypican-3 staining was found in 70% of HCCs and negative staining was seen in all non-tumor areas. An autophagy defect leading to increased expression of p62 and glypican-3 was also seen in the HCC cell line (Huh-7.5), but not in the primary human hepatocytes. Activation of cellular autophagy in Huh-7.5 cells efficiently cleared p62 and glypican-3 expression and inhibition of autophagy induced the expression of p62 and glypican-3. CONCLUSIONS: This study shows that p62 is increased in HCC compared to the surrounding non-tumorous liver tissue suggesting that human HCCs are autophagy defective. We provide further evidence that glypican-3 expression in HCC may also be related to defective autophagy. Our study indicates that p62 immunostain may represent a novel marker for HCC.

In vivo anticancer synergy mechanism of doxorubicin and verapamil combination treatment is impaired in BALB/c mice with metastatic breast cancer.

The development of resistance to anticancer drugs is a major unsolved problem in the chemotherapy treatment of metastatic breast cancer. We have shown that increased expression of P-glycoprotein (P-gp) prevented nuclear entry of the doxorubicin molecules into murine breast cancer cells (4T1-R) leading to doxorubicin chemoresistance. This study was performed to test whether inhibition of P-gp using verapamil could overcome doxorubicin chemoresistance and eliminate multiorgan metastasis 4T1-R cells in BALB/c mouse. The 4T1-R cells were treated with doxorubicin alone, verapamil alone, and a combination of both. Multiorgan metastasis of 4T1-R cells in the presence and in the absence of combination treatment was determined in the BALB/c mouse model. Verapamil induced nuclear translocation of doxorubicin, G2-phase growth arrest and synergistically induced 100% cytotoxicity in 4T1-R cells in culture. However, the combination treatment using verapamil and doxorubicin did not improve the overall survival of BALB/c mice with metastatic breast cancer. Our results indicate that the combination treatment of verapamil and doxorubicin did not inhibit tumor growth in the lungs and liver indicating that the anticancer synergy mechanism of verapamil and doxorubicin is impaired in vivo in BALB/c mouse model with metastatic breast cancer. We propose that understanding the mechanisms as to why the combination of doxorubicin and verapamil treatment was impaired in the mouse model should allow novel approaches to improve chemotherapy response of metastatic breast cancer.

Mechanisms of Sorafenib Resistance in HCC Culture Relate to the Impaired Membrane Expression of Organic Cation Transporter 1 (OCT1).

Introduction: Sorafenib, an FDA-approved drug for advanced hepatocellular carcinoma (HCC) treatment, encounters resistance in many patients. Deciphering the mechanisms underlying sorafenib resistance is crucial for devising alternative strategies to overcome it. Aim: This study aimed to investigate sorafenib resistance mechanisms using a diverse panel of HCC cell lines. Methods: HCC cell lines were subjected to continuous sorafenib treatment, and stable cell lines (Huh 7.5 and Huh 7PX) exhibiting sustained growth in its presence were isolated. The investigation of drug resistance mechanisms involved a comparative analysis of drug-targeted signal transduction pathways (EGFR/RAF/MEK/ERK/Cyclin D), sorafenib uptake, and membrane expression of the drug uptake transporter. Results: HCC cell lines (Huh 7.5 and Huh 7PX) with a higher IC50 (10µM) displayed a more frequent development of sorafenib resistance compared to those with a lower IC50 (2-4.8µM), indicating a potential impact of IC50 variation on initial treatment response. Our findings reveal that activated overexpression of Raf1 kinases and impaired sorafenib uptake, mediated by reduced membrane expression of organic cation transporter-1 (OCT1), contribute to sorafenib resistance in HCC cultures. Stable expression of the drug transporter OCT1 through cDNA transfection or adenoviral delivery of OCT1 mRNA increased sorafenib uptake and successfully overcame sorafenib resistance. Additionally, consistent with sorafenib resistance in HCC cultures, cirrhotic liver-associated human HCC tumors often exhibited impaired membrane expression of OCT1 and OCT3. Conclusion: Intrinsic differences among HCC cell clones, affecting sorafenib sensitivity at the expression level of Raf kinases, drug uptake, and OCT1 transporters, were identified. This study underscores the potential of HCC tumor targeted OCT1 expression to enhance sorafenib treatment response.

Increased expression of P-glycoprotein and doxorubicin chemoresistance of metastatic breast cancer is regulated by miR-298.

MicroRNAs (miRNAs) are short, noncoding RNA molecules that regulate the expression of a number of genes involved in cancer; therefore, they offer great diagnostic and therapeutic targets. We have developed doxorubicin-resistant and -sensitive metastatic human breast cancer cell lines (MDA-MB-231) to study the chemoresistant mechanisms regulated by miRNAs. We found that doxorubicin localized exclusively to the cytoplasm and was unable to reach the nuclei of resistant tumor cells because of the increased nuclear expression of MDR1/P-glycoprotein (P-gp). An miRNA array between doxorubicin-sensitive and -resistant breast cancer cells showed that reduced expression of miR-298 in doxorubicin-resistant human breast cancer cells was associated with increased expression of P-gp. In a transient transfection experiment, miR-298 directly bound to the MDR1 3' untranslated region and regulated the expression of firefly luciferase reporter in a dose-dependent manner. Overexpression of miR-298 down-regulated P-gp expression, increasing nuclear accumulation of doxorubicin and cytotoxicity in doxorubicin-resistant breast cancer cells. Furthermore, down-regulation of miR-298 increased P-gp expression and induced doxorubicin resistance in sensitive breast cancer cells. In summary, these results suggest that miR-298 directly modulates P-gp expression and is associated with the chemoresistant mechanisms of metastatic human breast cancer. Therefore, miR-298 has diagnostic and therapeutic potential for predicting doxorubicin chemoresistance in human breast cancer.