Zinc Finger E-Box Binding Homeobox 1 Promotes Cholangiocarcinoma Progression Through Tumor Dedifferentiation and Tumor-Stroma Paracrine Signaling.

BACKGROUND AND AIMS: Zinc finger E-box binding homeobox 1 (ZEB1) is a transcription factor that promotes metastatic and stem cell features, which has been associated with poor prognosis in cholangiocarcinoma (CCA), a desmoplastic cancer enriched in cancer-associated fibroblasts (CAFs). We aimed to define ZEB1 regulatory functions in malignant and stromal compartments of CCA. APPROACH AND RESULTS: Bioinformatic and immunohistochemical analyses were performed to determine correlations between ZEB1 and markers of progressiveness in human intrahepatic CCA (iCCA). Gain-of-function and loss-of-function models were generated in CCA cells and liver myofibroblasts as a model of CAFs. Conditioned media (CM) was used to unravel tumor-stroma interplay. In vivo experiments were performed using a xenograft CCA model. ZEB1 expression in tumor cells of human iCCA was associated with undifferentiated tumor and vascular invasion. In vitro, ZEB1 promoted epithelial-mesenchymal transition and stemness in tumor cells, leading to cell migration and spheroid formation. In vivo, ZEB1-overexpressing CCA cells formed larger tumors with more abundant stroma. Expression of cellular communication network factor 2 (CCN2, encoding connective tissue growth factor [CTGF]) was increased in tumor cells from ZEB1-overexpressing xenografts and correlated with ZEB1 expression in human tumors. In vitro, CM from ZEB1-overexpressing tumor cells or recombinant CTGF induced myofibroblast proliferation. ZEB1 was also expressed by CAFs in human CCA, and its expression correlated with CCN2 in myofibroblasts and CCA stroma. In mice, cotransplantation of CCA cells with ZEB1-depleted myofibroblasts reduced CCA progressiveness compared to CCA cells/ZEB1-expressing myofibroblasts. Furthermore, ZEB1 controls the expression of paracrine signals (i.e., HGF and IL6) in tumor cells and myofibroblasts. CONCLUSIONS: ZEB1 plays a key role in CCA progression by regulating tumor cell-CAF crosstalk, leading to tumor dedifferentiation and CAF activation.

Prevalence and risk factors of transmission of hepatitis delta virus in pregnant women in the Center Region of Cameroon.

BACKGROUND: Hepatitis B virus (HBV) and hepatitis delta virus (HDV) co-infection has been described as the most severe form of viral hepatitis, and can be co-transmitted from mother-to-child. A seroprevalence of 4.0% of HDV infection was reported in pregnant women in Yaoundé, and 11.9% in the general population in Cameroon. Our objective was to describe the rate of HDV infection in HBsAg-positive pregnant women and to determine risk factors associated with mother-to-child transmission of HDV. MATERIALS AND METHODS: A cross-sectional, descriptive study was conducted from January 2019 to July 2022 among pregnant women attending antenatal contacts in seven health structures in the Centre Region of Cameroon. A consecutive sampling (non-probability sampling) was used to select only pregnant women of age over 21 years, who gave a written informed consent. Following an informed consent, an open-ended questionnaire was used for a Knowledge, Attitude and Practice (KAP) survey of these women, and their blood specimens collected and screened for HBsAg, anti-HIV and anti-HCV antibodies by rapid tests and ELISA. HBsAg-positive samples were further screened for HBeAg, anti-HDV, anti-HBs, and anti HBc antibodies by ELISA, and plasma HDV RNA load measured by RT-qPCR. RESULTS: Of 1992 pregnant women, a rate of 6.7% of HBsAg (133/1992) with highest rate in the rural areas, and 3.9% of hepatitis vaccination rate were recorded. Of 130, 42 (32.3%) were anti-HDV antibody-positive, and 47.6% had detectable HDV RNA viraemia. Of 44 anti-HDV-positive cases, 2 (4.5%) were co-infected with HBV and HCV, while 5 (11.4%) with HIV and HBV. Multiple pregnancies, the presence of tattoos and/or scarifications were significantly associated with the presence of anti-HDV antibodies. Of note, 80% of women with negative HBeAg and positive anti-HBe serological profile, had plasma HDV RNA load of more than log 3.25 (>10.000 copies/ml). CONCLUSION: These results show an intermediate rate of HDV infection among pregnant women with high level of HDV RNA viremia, which suggest an increased risk of vertical and horizontal co-transmission of HDV.

Toward the elimination of hepatitis B: networking to promote the prevention of vertical transmission of hepatitis B virus through population-based interventions and multidisciplinary groups in Africa.

The WHO African Region had 81 million people with chronic hepatitis B in 2019, which remains a silent killer. Hepatitis B virus (HBV), hepatitis delta virus (HDV), and HIV can be transmitted from the mother to child. If the HBV infection is acquired at infancy, it may lead to chronic hepatitis B in 90% of the cases. WHO reports that 6.4 million children under 5 years live with chronic hepatitis B infection worldwide. The prevention of mother-to-child transmission (PMTCT) of HBV is therefore critical in the global elimination strategy of viral hepatitis as we take lessons from PMTCT of HIV programs in Africa. We sought to create a network of multidisciplinary professional and civil society volunteers with the vision to promote cost-effective, country-driven initiatives to prevent the MTCT of HBV in Africa. In 2018, the Mother-Infant Cohort Hepatitis B Network (MICHep B Network) with members from Cameroon, Zimbabwe, and the United Kingdom and later from Chad, Gabon, and Central African Republic was created. The long-term objectives of the network are to organize capacity-building and networking workshops, create awareness among pregnant women, their partners, and the community, promote the operational research on MTCT of HBV, and extend the network activities to other African countries. The Network organized in Cameroon, two "Knowledge, Attitude and Practice" (KAP) surveys, one in-depth interview of 45 health care workers which revealed a high acceptability of the hepatitis B vaccine by families, two in-person workshops in 2018 and 2019, and one virtual in 2021 with over 190 participants, as well as two workshops on grant writing, bioethics, and biostatistics of 30 postgraduate students. Two HBV seroprevalence studies in pregnant women were conducted in Cameroon and Zimbabwe, in which a prevalence of 5.8% and 2.7%, respectively, was reported. The results and recommendations from the MICHep B Network activities could be implemented in countries of the MICHep B Network and beyond, with the goal of providing free birth dose vaccine against hepatitis B in Africa.

The IGF2/IR/IGF1R Pathway in Tumor Cells and Myofibroblasts Mediates Resistance to EGFR Inhibition in Cholangiocarcinoma.

Purpose: Cholangiocarcinoma (CCA) is a desmoplastic tumor of the biliary tree in which epidermal growth factor receptor (EGFR) is overexpressed and contributes to cancer progression. Although EGFR has been envisaged as a target for therapy, treatment with tyrosine kinase inhibitors (TKI) such as erlotinib did not provide therapeutic benefit in patients with CCA, emphasizing the need to investigate resistance mechanisms against EGFR inhibition.Experimental Design: Resistant CCA cells to EGFR inhibition were obtained upon long-time exposure of cells with erlotinib. Cell signaling, viability, migration, and spheroid growth were determined in vitro, and tumor growth was evaluated in CCA xenograft models.Results: Erlotinib-resistant CCA cells displayed metastasis-associated signatures that correlated with a marked change in cell plasticity associated with an epithelial-mesenchymal transition (EMT) and a cancer stem cell (CSC)-like phenotype. Resistant cells exhibited an upregulation of insulin receptor (IR) and insulin-like growth factor (IGF) 1 receptor (IGF1R), along with an increase in IGF2 expression. IR/IGF1R inhibition reduced EMT and CSC-like traits in resistant cells. In vivo, tumors developed from resistant CCA cells were larger and exhibited a more prominent stromal compartment, enriched in cancer-associated fibroblasts (CAF). Pharmacological coinhibition of EGFR and IR/IGF1R reduced tumor growth and stromal compartment in resistant tumors. Modeling of CCA-CAF crosstalk showed that IGF2 expressed by fibroblasts boosted IR/IGF1R signaling in resistant cells. Furthermore, IR/IGF1R signaling positively regulated fibroblast proliferation and activation.Conclusions: To escape EGFR-TKI treatment, CCA tumor cells develop an adaptive mechanism by undergoing an IR/IGF1R-dependent phenotypic switch, involving a contribution of stromal cells. Clin Cancer Res; 24(17); 4282-96. ©2018 AACR.