BackgroundThe possible role of secretory products of fibrous tissue in the development of hepatocellular carcinoma (HCC) complicating chronic hepatitis C was investigated. Our hypothesis was that gremlin, secreted by fibroblasts, inhibited bone morphogenic protein (BMP), which mediates stem cell maturation into adult functioning hepatocytes, and thus, arrest stem cell maturation and promoted their proliferation in an immature state possibly culminating into development of HCCs.ResultsProtein expression of cytokeratin 19 (CK19) and fibroblast growth factor 2 (FGF-2), and mRNA expression of gremlin and BMP-7 were studied in 35 cases of chronic hepatitis, cirrhosis and HCC complicating chronic hepatitis C. CK19 expression was higher in cases of cirrhosis (0.004), which correlated with the grade (r = 0.64, p = 0.009) and stage (r = 0.71, p = 0.001). All HCCs were negative for CK19. Stem cell niche activation (as indicated as a ductular reaction) was highest in cases of cirrhosis (p = 0.001) and correlated with CK19 expression (r = 0.42, p = 0.012), the grade(r = 0.56, p = 0.024) and stage (0.66, p = 0.006). FGF-2 expression was highest in HCCs and correlated with the grade (r = 0.6, p = 0.013), stage (0.72, p = 0.002), CK19 expression (r = 0.71, p = 002) and ductular reaction (0.68, p = 0.004) in hepatitis cases. Higher numbers of cirrhosis cases and HCCs (p = 0.009) showed gremlin expression, which correlated with the stage (r = 0.7, p = 0.002). Gremlin expression correlated with that of CK19 (r = 0.699, p = 0.003) and FGF2 (r = 0.75, p = 0.001) in hepatitis cases.ConclusionsFibrosis promotes carcinogenesis by fibroblast-secreted gremlin that blocks BMP function and promotes stem cell activation and proliferation as well as possibly HCC development.

Increased expression of Yes-associated protein-1 ( YAP1 ) was shown to correlate with reduced survival in breast cancer (BC) patients. However, the exact mechanism of YAP1 regulation in BC cells remains ambiguous. Genomic sequence search showed that the promoter region of the YAP1 gene contains CpG Islands, hence the likelihood of epigenetic regulation by DNA methylation. To address this possibility, the effect of estrogen (17β estradiol; E2) on YAP1 gene expression and YAP1 promoter methylation status was evaluated in BC cells. The functional consequences of E2 treatment in control and YAP1 -silenced BC cells were also investigated. Our data showed that E2 modulates YAP1 expression by hypomethylation of its promoter region via downregulation of DNA methyltransferase 3B (DNMT3B); an effect that seems to facilitate tumor progression in BC cells. Although the effect of E2 on YAP1 expression was estrogen receptor (ER) dependent, E2 treatment also upregulated YAP1 expression in MDA-MB231 and SKBR3 cells, which are known ER-negative BC cell lines but expresses ERα. Functionally, E2 treatment resulted in increased cell proliferation, decreased apoptosis, cell cycle arrest, and autophagic flux in MCF7 cells. The knockdown of the YAP1 gene reversed these carcinogenic effects of E2 and inhibited E2-induced autophagy. Lastly, we showed that YAP1 is highly expressed and hypomethylated in human BC tissues and that increased YAP1 expression correlates negatively with DNMT3B expression but strongly associated with ER expression. Our data provide the basis for considering screening of YAP1 expression and its promoter methylation status in the diagnosis and prognosis of BC.

Objective: To investigate, in detail, the effects of rituximab (RTX), an off-label drug for treating multiple sclerosis (MS) disease on preventing and/or ameliorating experimental autoimmune encephalomyelitis (EAE). Methods: Using bioinformatics analysis of publicly available transcriptomics data, we determined the accumulation of B cells, plasma cells and T cells in different compartments of multiple sclerosis patients (MS) and healthy individual brains. Based on these observations and on the literature search, we dosed RTX in EAE mice either orally, or injected intraperitoneally (IP). The latter route was used either prophylactically (asymptomatic stage; upon the induction of the disease), or therapeutically (acute stage; upon the appearance of the first sign of the disease). Further, we used RTX as a preventive drug either as a single agent or in combination with other routes of administration. Results: Because no complete recovery was observed when RTX was used prophylactically or therapeutically, we devised another protocol of injecting this drug before the onset of the disease and designated this regiment as prevention. We demonstrated that the 20 μg/mouse prevention completely reduced the EAE clinical score, impaired infiltration of T and B cells into the perivascular space of mice brains, along with inhibiting the inflammation and demyelination. However, the 5 and 10 μg/mouse doses although reduced all aspects of inflammation in these mice, their effects were not as potent as the 20 μg/mouse RTX dose. Finally, we combined the 5 μg/mouse prevention treatment with either the prophylactic or therapeutic regimen and observed a robust effect. Conclusion: We observed that combinatorial regimens resulted in further reduction of inflammation, T and B cell extravasation into the brains of EAE mice and improved the remyelination.

Purpose The deregulation of the Hippo pathway results in translocation ofYes-associated protein-1 (YAP1) to the nucleus to exert an oncogenic effect. This effect has been demonstrated in several malignancies, yet, in breast cancer (BC), it remains controversial. The present study aimed to investigate the significance of YAP1 expression in BC, its relation to cancer stem cells (CSCs), and the effect of its inhibition on tumor cell survival. Patients and Methods We evaluated the expression of YAP1 protein and gene using immunohistochemistry (IHC) and RT-qPCR in FFPE tissue from normal and breast cancer cases. We also studied its association with CSC expression ( OCT4, NANOG , and SOX2 ) and with different clinicopathologic characteristics. Two BC cell lines (MCF7 and MDA-MB-231) were exposed to different concentrations of YAP1 inhibitor “verteporfin” and cell viability was subsequently assessed. Results YAP1 mRNA was higher in BC compared to the normal breast tissue (p-value=0.040) and was higher in luminal tumors compared to triple-negative breast cancer (TNBC) (p-value= 0.017). Its expression in tumors was significantly associated with the expression of pluripotency markers ( OCT4 and NANOG ) (p-value= 0.030 and 0.035, respectively) and its inhibition resulted in a significant reduction of CSC expression in both MCF-7 and MDA-MB-231 cells. YAP1 nuclear expression by IHC, which signifies its activation, was more evident in invasive carcinomas compared to normal breast tissue and in-situ foci where the expression was limited to the cytoplasm. The pretreatment of BC cells (MCF7 and MDA-MB-231) with YAP1 inhibitor “verteporfin” resulted in their sensitization to the effect of tamoxifen and doxorubicin, respectively, and significantly decreased tumor cell proliferation and survival. Conclusion Our results imply that YAP1 is highly expressed and activated in BC and its inhibition could represent a possible novel therapeutic strategy that should be further explored and investigated to improve the outcome of breast cancer patients.