Intraperitoneal metastasis is a common occurrence and is usually involved in the poor prognosis of ovarian cancer. Its specific metastatic pattern implies that certain indispensable microenvironmental factors secreted in the peritoneal cavity can direct metastatic ovarian cancer cells to permissive niches for secondary lesion formation. However, the underlying molecular mechanisms are ill defined. Herein, we report that GRO-α and IL-8 are predominately upregulated in culture media derived from either normal or cancerous omenta and are associated with increased ovarian cancer aggressiveness.Methods: OCM was established from culture medium of fresh human omental tissues. Primary and metastatic ovarian cancer cell lines were generated from human tumor tissues and verified by specific antibodies. The functional roles of GRO-α, IL-8, and their specific receptor CXCR2 were examined by neutralizing antibodies, shRNA gene knockdown, CRISPR/Cas9 gene knockout and pharmaceutical CXCR2 inhibitor SB225002. The oncogenic properties of ovarian cancer cells were examined by in vitro and in vivo mouse models.Results: Both GRO-α and IL-8 can activate TAK1/NFκB signaling via the CXCR2 receptor. Intriguingly, TAK1/NFκB signaling activity was higher in metastatic ovarian cancer cells; this higher activity makes them more susceptible to OCM-induced tumor aggressiveness. Treatment of ovarian cancer cells with GRO-α and IL-8 neutralizing antibodies or ablation of CXCR2 by shRNA gene knockdown, CRISPR/Cas9 gene knockout, or CXCR2 inhibitor SB225002 treatment significantly attenuated TAK1/NFκB signaling and decreased in vitro and in vivo oncogenic and metastatic potential, suggesting CXCR2 plays a key role in the GRO-α and IL-8-governed metastatic spreading of ovarian cancer cells in the intraperitoneal cavity.Conclusion: This study highlights the significance of GRO-α and IL-8 as the key chemokines in the peritoneal tumor microenvironment and suggests the utility of targeting their receptor CXCR2 as a potential target-based therapy for peritoneal metastases of ovarian cancer.

Transforming growth factor (TGF)-β-activating kinase 1 (TAK1) is a serine/threonine kinase which is frequently associated with human cancer progression. However, its functional role in tumorigenesis is still controversial. Here, we report that TAK1 enhances the oncogenic capacity of ovarian cancer cells through the activation of NF-κB signaling. We found that TAK1 is frequently upregulated and significantly associated with high-grade and metastatic ovarian cancers. Mechanistic studies showed that Ser412 phosphorylation is required for TAK1 in activating NF-κB signaling and promotes aggressiveness of ovarian cancer cells. Conversely, suppression of TAK1 activity by point mutation at Ser412, RNAi mediated gene knockdown or TAK1 specific inhibitor ((5Z) -7-Oxozeaenol) remarkably impairs tumor growth and metastasis in ovarian cancer in vitro and in vivo. Our study underscores the importance of targeting TAK1 as a promising therapeutic approach to counteract the ovarian cancer progression.

Accumulating evidence indicates that the human papillomavirus (HPV) E6 protein plays a crucial role in the development of cervical cancer. Subpopulations of cells that reside within tumours are responsible for tumour resistance to cancer therapy and recurrence. However, the identity of such cells residing in cervical cancer and their relationship with the HPV-E6 protein have not been identified. Here, we isolated sphere-forming cells, which showed self-renewal ability, from primary cervical tumours. Gene expression profiling revealed that cluster of differentiation (CD) 55 was upregulated in primary cervical cancer sphere cells. Flow-cytometric analysis detected abundant CD55(+) populations among a panel of HPV-positive cervical cancer cell lines, whereas few CD55(+) cells were found in HPV-negative cervical cancer and normal cervical epithelial cell lines. The CD55(+) subpopulation isolated from the C33A cell line showed significant sphere-forming ability and enhanced tumourigenicity, cell migration, and radioresistance. In contrast, the suppression of CD55 in HPV-positive CaSki cells inhibited tumourigenicity both in vitro and in vivo, and sensitized cells to radiation treatment. In addition, ectopic expression of the HPV-E6 protein in HPV-negative cervical cancer cells dramatically enriched the CD55(+) subpopulation. CRISPR/Cas9 knockout of CD55 in an HPV-E6-overexpressing stable clone abolished the tumourigenic effects of the HPV-E6 protein. Taken together, our data suggest that HPV-E6 protein expression enriches the CD55(+) population, which contributes to tumourigenicity and radioresistance in cervical cancer cells. Targeting CD55 via CRISPR/Cas9 may represent a novel avenue for developing new strategies and effective therapies for the treatment of cervical cancer. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Background CD109 was involved in the tumorigenesis and progression of various cancers via TGF-β1 signalling and STAT3 activation. As CD109 is strongly expressed in cervical squamous cell carcinoma, this study was conducted to investigate its functional characteristics in cervical cancer. Methods CD109 expression was examined by immunohistochemistry (IHC) with cervical tissue microarray. The effects of CD109 expression were examined on migration, cell proliferation, spheroid formation and soft-agar colony-formation assay. Meanwhile, cervical cancer cell lines with high CD109 expression were chosen for the functional study using siRNA knockdown and CRISPR/Cas9 knockout. Results IHC demonstrated an upregulation of CD109 in the cell membrane of cervical squamous cell carcinoma. CD109( + ) cells isolated by flow-cytometric sorting displayed enhanced migration, cell proliferation, sphere-forming and anchorage-independent cell growth ability. In contrast, silencing of CD109 expression could reverse the in vitro and in vivo tumorigenic and aggressive properties. Furthermore, CD109 induced EGFR-mediated STAT3 phosphorylation known to be responsible for cell migration, proliferation and maintenance of CSC phenotype. Conclusion Abundant CD109( + ) populations in cervical cancer cells potentially contributed to carcinogenesis and aggressiveness, whereas silencing of CD109 expression could reverse those properties. CD109 mediates cervical tumorigenicity and aggressiveness via CD109/EGFR/STAT3 signalling.