Fatty Acid-Binding Protein 4 (FABP4) Suppresses Proliferation and Migration of Endometrial Cancer Cells via PI3K/Akt Pathway.

PURPOSE: Endometrial cancer (EC) is the sixth most common cancer in women and its incidence and mortality have been rising over the last decades. The latest research indicates that FABP4 plays a significant role in multiple types of cancer. But few studies were focused on EC. The aim of this article is to investigate whether FABP4 can suppress tumor growth and metastasis of EC via PI3K/Akt pathway to provide a novel therapeutic target for the treatment of EC. MATERIALS AND METHODS: FABP4 mRNA levels of EC were analysed through The Cancer Genome Atlas database (TCGA), and expression of FABP4 in EC cancer tissues was determined by immunohistochemistry (IHC) assays. Stable overexpressing cell lines were established using lentivirus infection to analyze the biological function of FABP4 in vitro. CCK8 assay and colony formation assay were performed to assess cell proliferation ability. Wound healing assay and transwell were performed to analyse migration and invasion of cells. The subcutaneous xenograft mouse model was used to evaluate tumor growth in vivo. Additionally, all protein levels were detected by Western blotting assay. RESULTS: We found that the expression of the FABP4 mRNA was decreased in tumor samples compared to normal tissue according to TCGA database analysis. Subsequent experimental mRNA and protein expression analysis confirmed that FABP4 expression was lower in EC tissue than normal endometrial tissue. In addition, we found overexpression of FABP4 inhibited the proliferation, migration and invasion in vitro and suppressed tumor growth in vivo. Further functional and mechanistic analysis of FABP4 demonstrated that its function is mediated by restraining the phosphorylation of PI3K/Akt signaling pathway. CONCLUSION: Our studies shed light for the first time about the functional role of FABP4 in EC and provide a novel biomarker for EC as well as a therapeutic target for the therapy of EC.

OSU-03012 Disrupts Akt Signaling and Prevents Endometrial Carcinoma Progression in vitro and in vivo.

PURPOSE: OSU-03012 is a celecoxib derivative lacking cyclooxygenase-2 inhibitory activity and a potent PDK1 inhibitor which has been shown to inhibit tumor growth in various ways. However, the role of OSU-03012 in endometrial carcinoma (EC) in which the PI3K/Akt signaling pathway highly activated has not been studied. Here, we determined the potency of OSU-03012 in suppressing EC progression in vitro and in vivo, and studied the underlined mechanisms. METHODS: The human EC Ishikawa and HEC-1A cells were used as the in vitro models. CCK8 assay and flow cytometry were conducted to evaluate cell proliferation, cell cycle progression, and apoptosis. The metastatic ability was evaluated using the transwell migration assay. The Ishikawa xenograft tumor model was used to study the inhibitory effects of OSU-03012 on EC growth in vivo. Western blot analysis was performed to evaluate expressions of the cell cycle and apoptosis associated proteins. RESULTS: OSU-03012 could inhibit the progression of EC both in vitro and in vivo by disrupting Akt signaling. It reduced the metastatic ability of EC, led to G2/M cell cycle arrest and induced apoptosis via the mitochondrial apoptosis pathway. CONCLUSION: Our data indicated that OSU-03012 could inhibit the progression of EC in vitro and in vivo. It can potentially be used as the targeted drug for the treatment of EC by inhibiting Akt signaling.

Williams syndrome transcription factor promotes proliferation and invasion of cervical cancer cells by regulating PI3K/Akt signaling pathway.

OBJECTIVE: This study aimed to investigate the expression of Williams Syndrome transcription factor (WSTF) in cervical cancer (CC) tissues and cells, the effect on the proliferation, migration, invasion, and the molecular mechanism of WSTF in CC cells to find a new biomarker. MATERIALS AND METHODS: The expression of WSTF in tissues was detected by real-time quantitative polymerase chain reaction (RT-qPCR) and/or immunohistochemistry. Human CC cell lines and human normal cervical epithelial cell lines were detected by RT-qPCR. Lentivirus-mediated gene transfected in Siha/CaSki cells. The transfection efficiency of lentivirus was observed by a fluorescence microscope, RT-qPCR, and western blot. After transfection, the proliferation of Siha/CaSki cells was detected by CCK-8 assay and colony formation assay. The migration and invasion of Siha/CaSki cells were detected by transwell assay and wound healing assay. Western blot assay were used to detect the expression of WSTF and PI3K/Akt-related proteins in Siha/CaSki cells. RESULTS: The expression of WSTF in CC tissues was higher than that in adjacent tissues (p < 0.05). The expression of WSTF in CC cells was higher than that in normal cervical epithelial cells (p < 0.01). Downregulation of WSTF expression could inhibit the proliferation, migration, and invasion of CC cells (p < 0.01). WSTF overexpression activates PI3K/Akt signaling pathway (p < 0.01). CONCLUSION: WSTF is highly expressed in CC tissues and cells, and downregulation of WSTF can inhibit the proliferation, invasion, and migration of CC cells by activating the PI3K/Akt signaling pathway. WSTF is a very promising new biomarker for CC.

RPL34-AS1-induced RPL34 inhibits cervical cancer cell tumorigenesis via the MDM2-P53 pathway.

Ribosomal proteins (RPs) are important components of ribosomes and related to the occurrence and development of tumors. However, little is known about the effects of the RP network on cervical cancer (CC). In this study, we screened differentially expressed RPL34 in CC by high-throughput quantitative proteome assay. We found that RPL34 acted as a tumor suppressor and was downregulated in CC and inhibited the proliferation, migration, and invasion abilities of CC cells. Next, we verified that RPL34 regulated the CC through the MDM2-P53 pathway by using Act D medicine, MDM2 inhibitor, and a series of western blotting（WB）assays. Moreover, an antisense lncRNA, RPL34-AS1, regulated the expression of RPL34 and participated in the tumorigenesis of CC. RPL34 can reverse the effect of RPL34-AS1 in CC cells. Finally, by RNA-binding protein immunoprecipitation (RIP) assay we found that eukaryotic initiation factor 4A3 (EIF4A3), which binds to RPL34-AS1, regulated RPL34-AS1 expression in CC. Therefore, our findings indicate that RPL34-AS1-induced RPL34 inhibits CC cell proliferation, invasion, and metastasis through modulation of the MDM2-P53 signaling pathway, which provides a meaningful target for the early diagnosis and treatment of CC.

Silencing of circular RNA_0000326 inhibits cervical cancer cell proliferation, migration and invasion by boosting microRNA-338-3p-dependent down-regulation of CDK4.

Cervical cancer is one of the leading causes of cancer-related death among women, which is attributed partly by limited treatment options. Recent studies have provided in-depth explanations regarding the role of circular RNA in cancers. We aimed to investigate the role of circular RNA_0000326 in cervical cancer. Bioinformatics analysis revealed a high circ_0000326 expression in cervical cancer. Cervical cancer cells and tissues were also observed to have elevated levels of circ_0000326 and the upregulation of circ_0000326 depended on the stage of cancer. Transfection with siRNA of circ_0000326 resulted in the inhibition of proliferation, migration and cell cycle of cancer cells. Interestingly, we confirmed that circ_0000326 served as a sponge for microRNA-338-3p and that the miRNA bound to Cyclin-dependent kinase 4. In the presence of microRNA-338-3p mimic or silencing of circ_0000326, Cyclin-dependent kinase 4 expression was decreased. Transfection with microRNA-338-3p mimic inhibited cell clone formation and proliferation. Moreover, in vivo experiment revealed that the injection of shRNA-circ_0000326 lentivirus suppressed tumor growth and decreased Cyclin-dependent kinase 4 expression. Taken altogether, our results showed that circ_0000326 exerted oncogenic effects on cervical cancer by upregulating Cyclin-dependent kinase 4 via sponging microRNA-338-3p. This systematic investigation on circ_0000326 could provide further insight into cervical cancer.

Prognostic and diagnostic validity of p16/Ki-67, HPV E6/E7 mRNA, and HPV DNA in women with ASCUS: a follow-up study.

BACKGROUND: We evaluated the prognostic and diagnostic ability of p16/Ki-67 immunocytochemistry, HPV E6/E7 mRNA testing and HPV DNA assay in triaging ASCUS to find a way to manage cervical lesions more effectively. METHODS: We conducted a prospective study through follow-up. The detection methods of the three factors: p16/Ki-67 immunocytochemistry conducted by using the CINtec® Plus Kit, E6/E7 mRNA testing by QuantiVirus®HPV E6/E7 mRNA assay and DNA by Hybrid Capture 2 assay. RESULTS: One hundred three women with ASCUS satisfied requirements and completed the entire follow-up process. All CIN2+ occurred in women who were mRNA positive at baseline, none in mRNA negative. 100% (6/6) patients with CIN2+ were HPV DNA assay positive, 100% (6/6) were HPV E6/E7 mRNA testing positive and 50.0% (3/6) were p16/Ki-67 immunocytochemistry positive. The risk ratio of E6/E7 mRNA test was 57.306 (95% CI 0.077-42,400.545). For endpoint of CIN2+, the sensitivity between HPV DNA assay and HPV E6/E7 mRNA testing is no statistical difference, but statistical difference exists between HPV E6/E7 mRNA testing vs. p16/Ki-67 immunocytochemistry (χ2 = 5.718, P = 0.023) and HPV DNA assay vs. p16/Ki-67 immunocytochemistry (χ2 = 5.718, P = 0.023). The specificity of E6/E7 mRNA testing, p16/Ki-67 and DNA assay in triaging ASCUS was 44.33, 75.26 and 11.34% respectively and is all statistical difference (χ2 = 26.277, P < 0.001(HPV DNA assay vs. HPV E6/E7 mRNA testing), χ2 = 19.297, P < 0.001(HPV E6/E7 mRNA testing vs. p16/Ki-67 immunocytochemistry), χ2 = 80.707, P < 0.001(HPV DNA assay vs. p16/Ki-67 immunocytochemistry). The expression level of 2097.09 copies/ml was the optimal cut-off value for HPV E6/E7 mRNA testing to diagnose CIN2+, the sensitivity and specificity was 61.1 and 68.2%. CONCLUSIONS: High expression of HPV E6/E7 mRNA could be a good candidate as a diagnostic biomarker to triage ASCUS superseding HPV DNA. p16/Ki-67 immunocytochemistry is suggested to be a good tool to triage ASCUS, but it reduced the sensitivity of diagnosis when improves the diagnostic specificity.