Lin-Hung Wei

Interleukin-6 promotes cervical tumor growth by VEGF-dependent angiogenesis via a STAT3 pathway.

Interleukin-6 (IL-6) has received particular attention in the pathogenesis of cervical cancer, although the underlying mechanism remains elusive. This study revealed that IL-6 promotes in vivo tumor growth of human cervical cancer C33A cells, but does not substantially alter their in vitro growth kinetics. The in vivo angiogenic assays showed that IL-6 increases angiogenic activity in human cervical cancer cells, an effect that is specifically associated with upregulation of vascular endothelial growth factor (VEGF). Also, using anti-VEGF antibody to block VEGF function significantly inhibited IL-6-mediated angiogenesis and tumor growth in nude mice, strongly supporting the critical role of VEGF in the IL-6-mediated cervical tumorigenesis. Accordingly, the signaling pathway downstream of IL-6/IL-6R responsible for the regulation of VEGF was investigated. Notably, pharmacological inhibition of PI3-K or MAPK failed to inhibit IL-6-mediated transcriptional upregulation of VEGF. Meanwhile, blocking STAT3 pathway with dominant-negative mutant STAT3D effectively abolished IL-6-induced VEGF mRNA. In transient transfections, a luciferase reporter construct containing the full-length 1.5-kb VEGF promoter or a 1.2-kb fragment lacking the known hypoxic-response element also exhibited the same degree of response to IL-6. Additionally, transient transfection of STAT3D downregulated the 1.2-kb VEGF promoter luciferase reporter stimulated by IL-6. Based on the above phenomenon combined with the concomitant increased tumor expression of IL-6 and VEGF in cervical cancer tissues, we conclude that IL-6 may promote cervical tumorigenesis by activating VEGF-mediated angiogenesis via a STAT3 pathway.

IL-6 Trans-Signaling in Formation and Progression of Malignant Ascites in Ovarian Cancer

Classic signaling by the proinflammatory cytokine interleukin 6 (IL-6) involves its binding to target cells that express the membrane-bound IL-6 receptor α. However, an alternate signaling pathway exists in which soluble IL-6 receptor (sIL-6Rα) can bind IL-6 and activate target cells that lack mIL-6Rα, such as endothelial cells. This alternate pathway, also termed trans-signaling, serves as the major IL-6 signaling pathway in various pathologic proinflammatory conditions including cancer. Here we report that sIL-6Rα is elevated in malignant ascites from ovarian cancer patients, where it is associated with poor prognosis. IL-6 trans-signaling on endothelial cells prevented chemotherapy-induced apoptosis, induced endothelial hyperpermeability, and increased transendothelial migration of ovarian cancer cells. Selective blockade of the MAPK pathway with ERK inhibitor PD98059 reduced IL-6/sIL-6Rα-mediated endothelial hyperpermeability. ERK activation by the IL-6/sIL-6Rα complex increased endothelial integrity via Src kinase activation and Y685 phosphorylation of VE-cadherin. Selective targeting of IL-6 trans-signaling in vivo reduced ascites formation and enhanced the taxane sensitivity of intraperitoneal human ovarian tumor xenografts in mice. Collectively, our results show that increased levels of sIL-6Rα found in ovarian cancer ascites drive IL-6 trans-signaling on endothelial cells, thereby contributing to cancer progression. Selective blockade of IL-6 trans-signaling may offer a promising therapeutic strategy to improve the management of patients with advanced ovarian cancer.

Vascular endothelial growth factor and prognosis of cervical carcinoma

Objective To evaluate vascular endothelial growth factor (VEGF) as a marker for predicting lymph node metastasis and an independent prognostic factor of early-stage cervical carcinoma. Methods One hundred thirty-five women with stage IB–IIA cervical carcinoma had radical abdominal hysterectomies and pelvic lymph node dissections. Intratumoral cytosol VEGF concentrations were assayed with enzyme immunoassay. Histopathologic items and cytosol VEGF-influencing clinical outcomes were compared. Results Twenty-two women (16.3%) who had disease recurrence had higher levels of cytosol VEGF (1020 versus 112 pg/mg protein, P < .001) than those without recurrence. Using a cutoff value of 400 pg/mg protein resulted in best sensitivity of 75%, best specificity of 70%, positive predictive value of 41%, and negative predictive value of 92%. Only overexpressed cytosol VEGF (hazard ratio 6.44, P < .001) was an independent prognostic factor of disease-free survival. The overexpressed cytosol VEGF (hazard ratio 4.50, P = .021) and positive lymphovascular emboli (hazard ratio 4.11, P = .045) were independent prognostic factor of overall survival. Conclusion Cytosol VEGF might be a biomarker for the status of pelvic lymph nodes in early-stage cervical carcinoma and an independent prognostic indicator of its outcome.

Arsenic trioxide prevents radiation-enhanced tumor invasiveness and inhibits matrix metalloproteinase-9 through downregulation of nuclear factor kappaB.

Arsenic trioxide (ATO) has been implicated as a promising anticancer agent by inhibiting cell growth and inducing apoptosis in certain types of cancer cells. This study explored the antimetastasis property of arsenic, drew potential link between arsenic use and radiotherapy, and uncovered the specific mechanisms underlying these remarkable responses. Using gelatin invasion assay and intravasation assay, we report the novel finding that low-dose ATO (1 μM) reduced the intrinsic migration ability of HeLa cells and significantly inhibited radiation-promoted tumor invasive potential of CaSki cells without inducing apoptotic cell death. Using the murine Lewis lung carcinoma model, the control animals and ATO treatment animals (1 mg/kg i.p., twice weekly) displayed similar in vivo growth kinetics, whereas the radiation (30 Gy in one fraction) and concurrent treatment groups showed considerable growth inhibition. Importantly, although concurrent treatment did not enhance the effectiveness of radiation therapy to the primary tumor, further examination of the lungs revealed that all animals succumbed to radiation-accelerated lung metastases could be effectively treated by combination of ATO and radiation. Radiation-induced matrix metalloproteinase-9 (MMP-9) expression was significantly inhibited by ATO using sequential analysis of the expression of MMPs in xenografts. Supporting this observation, ATO directly downregulates radiation-induced MMP-9 mRNA expression by inhibiting nuclear factor κB activity in human cervical cancer cells. In sum, concurrent arsenic–radiation therapy not only achieves local tumor control but also inhibits distant metastasis. Experimental results of this study highlight a novel strategy in cancer treatment.

The H3K9 methyltransferase G9a is a marker of aggressive ovarian cancer that promotes peritoneal metastasis

BackgroundOvarian cancer (OCa) peritoneal metastasis is the leading cause of cancer–related deaths in women with limited therapeutic options available for treating it and poor prognosis, as the underlying mechanism is not fully understood.MethodThe clinicopathological correlation of G9a expression was assessed in tumor specimens of ovarian cancer patients. Knockdown or overexpression of G9a in ovarian cancer cell lines was analysed with regard to its effect on adhesion, migration, invasion and anoikis-resistance. In vivo biological functions of G9a were tested by i.p. xenograft ovarian cancer models. Microarray and quantitative RT-PCR were used to analyze G9a-regulated downstream target genes.ResultsWe found that the expression of histone methyltransferase G9a was highly correlated with late stage, high grade, and serous-type OCa. Higher G9a expression predicted a shorter survival in ovarian cancer patients. Furthermore, G9a expression was higher in metastatic lesions compared with their corresponding ovarian primary tumors. Knockdown of G9a expression suppressed prometastatic cellular activities including adhesion, migration, invasion and anoikis-resistance of ovarian cancer cell lines, while G9a over-expression promoted these cellular properties. G9a depletion significantly attenuated the development of ascites and tumor nodules in a peritoneal dissemination model. Importantly, microarray and quantitative RT-PCR analysis revealed that G9a regulates a cohort of tumor suppressor genes including CDH1, DUSP5, SPRY4, and PPP1R15A in ovarian cancer. Expression of these genes was also inversely correlated with G9a expression in OCa specimens.ConclusionWe propose that G9a contributes to multiple steps of ovarian cancer metastasis and represents a novel target to combat this deadly disease.

Overexpression of Her-2/neu in epithelial ovarian carcinoma induces vascular endothelial growth factor C by activating NF-κB: Implications for malignant ascites formation and tumor lymphangiogenesis

Vascular endothelial growth factor C (VEGF-C) is an important growth factor that governs lymphatic spread and the development of intraperitoneal tumors associated with epithelial ovarian cancer; however, its regulation is not yet understood. Overexpression of Her-2/NEU is related to poor survival in advanced epithelial ovarian carcinoma patients. Accordingly, this study attempted to analyze the association between the Her-2/NEU oncogene and VEGF-C in ovarian carcinoma and to elucidate the molecular mechanism of VEGF-C induction by Her-2/NEU. Immunohistochemistry was used to determine the expression of Her-2/NEU and VEGF-C in tissues from 41 patients with epithelial ovarian carcinoma. Several Her-2/NEU-stably-transfected Caov-3 ovarian carcinoma cells were used to evaluate the effect of Her-2/NEU on VEGF-C, the possible regulation mechanism, and the biological function of VEGF-C. Our experimental results identified a significant association between the Her-2/NEU oncogene and VEGF-C expression in both epithelial ovarian cancer patients (p < 0.05; Fishers exact test) and in vitro cell lines. The overexpression of Her-2/NEU in Caov-3 ovarian cancer cells resulted in induction of a considerable amount of VEGF-C mRNA and protein; this process was dose-dependently inhibited by herceptin. The generation of VEGF-C significantly increased endothelial permeability. Pharmacological and genetic inhibition assays revealed that the cytoplasmic signaling molecule, p38 MAPK, and the transcriptional factor, NF-kappa B, are critically involved in the transcriptional activation of the VEGF-C gene by Her-2/NEU. In conclusion, this work clearly establishes that the Her-2/NEU oncogene is essential for the regulation of VEGF-C in ovarian carcinoma. It may be possible to use the monoclonal antibody targeting Her-2/NEU receptor to limit the formation of malignant ascites and lymphatic spread in ovarian carcinoma.

The Role of IL-6 Trans-Signaling in Vascular Leakage: Implications for Ovarian Hyperstimulation Syndrome in a Murine Model

CONTEXT The inflammatory cytokine IL-6 is related to ovarian hyperstimulation syndrome (OHSS), although the functional role of IL-6 in OHSS remains largely unknown. OBJECTIVE A key feature of the IL-6 response is that its regulation is dependent on IL-6 trans-signaling via soluble IL-6 receptor-α (sIL-6Rα). The objective of the study was to elucidate the mechanistic role of IL-6 trans-signaling in the vascular leakage that underlies the pathophysiology of OHSS. DESIGN Ovarian endothelial cells (ECs) and granulosa-lutein cells were obtained from women undergoing in vitro fertilization. OHSS was induced in mice by administering gonadotropins for 2 days followed by human chorionic gonadotropin. The functional role of IL-6 trans-signaling in OHSS was verified using the designer cytokines Hyper IL-6 and sgp130-Fc. RESULTS The follicular fluid levels of sIL-6Rα were elevated in women at high risk for OHSS. In the murine OHSS model, stimulation with gonadotropins significantly induces ovarian IL-6 and sIL-6Rα expression. In vitro, FSH induces de novo sIL-6Rα synthesis in granulosa-lutein cells through a protein kinase C-dependent pathway. In addition, sIL-6Rα was released by leukocytes in the presence of conditioned medium from human chorionic gonadotropin-treated granulosa-lutein cells. Ovarian ECs responded to the IL-6Rα-IL-6 complex (Hyper IL-6) but not to IL-6 alone. With activation of signal transducer and activator of transcription 3 (STAT3) and ERK, Hyper IL-6 increased vascular endothelial growth factor expression and the vascular permeability of ECs. Selective blockade of IL-6 trans-signaling by sgp130-Fc significantly inhibited vascular endothelial growth factor expression and prevented OHSS in mice. CONCLUSIONS IL-6 trans-signaling is activated during the ovarian stimulation process. Our findings provide insight into the biologic effects of IL-6 trans-signaling in OHSS and highlight that IL-6 trans-signaling can induce vascular leakage in this disease.

The possible use of colour flow Doppler in planning treatment in early invasive carcinoma of the cervix

Objective To investigate the pathological significance of intra‐tumoural blood flow signals detected by colour Doppler ultrasound and their association with angiogenesis in cervical carcinoma.

Histone Deacetylase 6 Regulates Estrogen Receptor α in Uterine Leiomyoma

Histone deacetylase 6 (HDAC) 6 is a regulatory factor in the endocrine traffic network that controls growth factor receptor stability. Histone deacetylase 6 expression and its pathogenic role in the uterine leiomyoma have not been studied. Here, we demonstrated that there was a consistent pattern of increasing HDAC6 and estrogen receptor (ER) α expression in leiomyoma samples. For all individual cases, expression of HDAC6 in the normal myometrium or leiomyoma positively correlated with ERα expression. The spearman’s rho (ρ) was .53 (P = .008) between HDAC6 and ERα in normal myometrium and, more significantly, the spearman rho was .80 (P < .001) between HDAC6 and ERα in leiomyoma. In ELT-3 leiomyoma cells, silencing HDAC6 expression substantially reduced ERα expression, lowered estrogen response, and inhibited ELT-3 cell growth. Our results, taken together, are the first to provide experimental evidence suggesting that HDAC6 may be an essential molecular therapeutic target in controlling leiomyoma growth.

Standardized uptake value and apparent diffusion coefficient of endometrial cancer evaluated with integrated whole-body PET/MR: Correlation with pathological prognostic factors

To evaluate the correlation between maximum standardized uptake value (SUVmax) and minimum apparent diffusion coefficient (ADCmin) of endometrial cancer derived from an integrated positron emission tomography / magnetic resonance (PET/MR) system and to determine their correlation with pathological prognostic factors.