Changyu Wang

Genome-wide profiling of HPV integration in cervical cancer identifies clustered genomic hot spots and a potential microhomology-mediated integration mechanism

Human papillomavirus (HPV) integration is a key genetic event in cervical carcinogenesis. By conducting whole-genome sequencing and high-throughput viral integration detection, we identified 3,667 HPV integration breakpoints in 26 cervical intraepithelial neoplasias, 104 cervical carcinomas and five cell lines. Beyond recalculating frequencies for the previously reported frequent integration sites POU5F1B (9.7%), FHIT (8.7%), KLF12 (7.8%), KLF5 (6.8%), LRP1B (5.8%) and LEPREL1 (4.9%), we discovered new hot spots HMGA2 (7.8%), DLG2 (4.9%) and SEMA3D (4.9%). Protein expression from FHIT and LRP1B was downregulated when HPV integrated in their introns. Protein expression from MYC and HMGA2 was elevated when HPV integrated into flanking regions. Moreover, microhomologous sequence between the human and HPV genomes was significantly enriched near integration breakpoints, indicating that fusion between viral and human DNA may have occurred by microhomology-mediated DNA repair pathways. Our data provide insights into HPV integration-driven cervical carcinogenesis.

TALEN-mediated targeting of HPV oncogenes ameliorates HPV-related cervical malignancy

Persistent HPV infection is recognized as the main etiologic factor for cervical cancer. HPV expresses the oncoproteins E6 and E7, both of which play key roles in maintaining viral infection and promoting carcinogenesis. While siRNA-mediated targeting of E6 and E7 transcripts temporarily induces apoptosis in HPV-positive cells, it does not eliminate viral DNA within the host genome, which can harbor escape mutants. Here, we demonstrated that specifically targeting E6 and E7 within host DNA with transcription activator-like effector nucleases (TALENs) induces apoptosis, inhibits growth, and reduces tumorigenicity in HPV-positive cell lines. TALEN treatment efficiently disrupted E6 and E7 oncogenes, leading to the restoration of host tumor suppressors p53 and retinoblastoma 1 (RB1), which are targeted by E6 and E7, respectively. In the K14-HPV16 transgenic mouse model of HPV-driven neoplasms, direct cervical application of HPV16-E7-targeted TALENs effectively mutated the E7 oncogene, reduced viral DNA load, and restored RB1 function and downstream targets transcription factor E2F1 and cycling-dependent kinase 2 (CDK2), thereby reversing the malignant phenotype. Together, the results from our study suggest that TALENs have potential as a therapeutic strategy for HPV infection and related cervical malignancy.

Akt Mediates Metastasis-Associated Gene 1 (MTA1) Regulating the Expression of E-cadherin and Promoting the Invasiveness of Prostate Cancer Cells

Human metastasis-associated gene 1 (MTA1) is highly associated with the metastasis of prostate cancer; however, the molecular functions of MTA1 that facilitate metastasis remain unclear. In this study, we demonstrate that the silencing of MTA1 by siRNA treatment results in the upregulation of E-cadherin expression by the phosphorylation of AKT (p-AKT) and decreases the invasiveness of prostate cancer cells. We show that MTA1 is expressed in over 90% of prostate cancer tissues, especially metastatic prostate cancer tissue, comparing to non-expression in normal prostate tissue. RT-PCR analysis and Western blot assay showed that MTA1 expression is significantly higher in highly metastatic prostate cancer PC-3M-1E8 cells (1E8) than in poorly metastatic prostate cancer PC-3M-2B4 cells (2B4). Silencing MTA1 expression by siRNA treatment in 1E8 cells increased the cellular malignant characters, including the cellular adhesive ability, decreased the cellular invasive ability and changed the polarity of cellular cytoskeleton. 1E8 cells over-expressing MTA1 had a reduced expression of E-cadherin, while 1E8 cells treated with MTA1 siRNA had a higher expression of E-cadherin. The expression of phosphorylated AKT (p-AKT) or the inhibition of p-AKT by wortmannin treatment (100 nM) significantly altered the function of MTA1 in the regulation of E-cadherin expression. Alterations in E-cadherin expression changed the role of p-AKT in cellular malignant characters. All of these results demonstrate that MTA1 plays an important role in controlling the malignant transformation of prostate cancer cells through the p-AKT/E-cadherin pathway. This study also provides a new mechanistic role for MTA1 in the regulation of prostate cancer metastasis.

Matched-case comparison of neoadjuvant chemotherapy in patients with FIGO stage IB1-IIB cervical cancer to establish selection criteria.

OBJECTIVE Neoadjuvant chemotherapy (NACT) for cervical cancer still remains controversial. NACT was evaluated to establish selection criteria. METHODS A matched-case comparison was designed for the NACT group (n=707) and primary surgery treatment (PST; n=707) group to investigate short-term responses and high/intermediate risk factors (HRFs/IRFs). The 5-year disease-free survival (DFS) and overall survival (OS) rates were stratified by NACT response, HRFs/IRFs, International Federation of Gynecology and Obstetrics (FIGO) stage and tumour size, respectively. RESULTS The clinical and pathological response rates were 79.3% and 14.9% in the NACT group. In comparison to the PST group, IRFs but not HRFs were significantly decreased (P<0.05), and the 5-year DFS rate was significantly improved in the NACT group (88.4% versus 83.1%, P=0.021). Moreover, the 5-year DFS and OS rates were favourably increased in the clinical responders in comparison to the PST group and the clinical non-responders (P<0.05). Compared to those of clinical non-responders, the 5-year DFS and OS rates of clinical responders, with or without HRFs, were also significantly increased (P<0.01). In stage IB2, the 5-year DFS and OS rates were significantly increased, whereas operation duration declined in the NACT group (P<0.05). For patients with stage IB tumours of 2-5 cm, the 5-year DFS and OS rates of clinical responders were significantly improved (P<0.05). CONCLUSIONS NACT is a suitable option for patients with cervical cancer, especially for NACT responders and patients with stage IB, which provides a new concept of fertility preservation for young patients.

Silencing Wnt2B by siRNA interference inhibits metastasis and enhances chemotherapy sensitivity in ovarian cancer.

Objective Wnt2B overexpression is thought to be involved in tumor progression through the activation of the canonical Wingless and INT-1 signaling pathway. However, the mechanism of Wnt2B signaling in oncogenesis is unknown. In this study, we investigated whether silencing Wnt2B expression could inhibit the invasiveness of ovarian cancer cells and reduce drug resistance. Methods/Materials Four ovarian carcinoma cell lines, SKOV3, OV2008, A2780, and C13K, were used. Protein levels were studied by Western blotting. The colony formation ability and invasive ability were determined through colony formation assay and the Matrigel transwell assay, respectively. Cell viability was determined by the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay, whereas apoptosis was assessed using flow cytometry analysis. Results Among the 4 ovarian carcinoma cell lines, the A2780 cells and C13K cells expressed Wnt2B, and these 2 cell lines were used for analyzing the mechanism of Wnt2B. The down-regulation of Wnt2B inhibited cell colony formation and invasiveness. Enhanced paclitaxel or cisplatin sensitivity was observed in A2780 cells or C13K cells treated with Wnt2B siRNA, respectively. In the presence of Wnt2B siRNA treatment, the caspase-9/B-cell lymphoma 2 (BCL2)/B-cell lymphoma-xL (BCL-xL) pathway and the epithelial-mesenchymal transition/phosphorylated protein kinase B pathway were inhibited. Conclusion These data suggest that Wnt2B indeed plays an important role in ovarian cancer metastasis and drug resistance. This study may provide a new therapeutic target for and a better understanding of ovarian cancer therapy.

TLR9 expression and its role in chemosensitivity to DDP in human cervical cancer cells in vitro.

SummaryInflammation and infection play an important role in the pathogenesis of many cancers. Toll-like receptors (TLRs) are a class of pattern recognition receptors that recognize conserved components of microbes and trigger the immune response against invading microorganisms. Toll-like receptor 9 (TLR9) recognizes non-methylated cytosine-phosphateguanosine (CpG) DNA sequences which are the surrogate for viral DNA. TLR9 may react to tumor development and progression during chronic inflammation that involves the tumor microenvironment. In order to study the role of TLR9 in cervical cancer, we analyzed the TLR9 expression in different types of HPV infection cervical cancer cells. Then we detected if CpG sequences influenced the TLR9 expression and the sensitivity to cisplatin (DDP) of these cervical cancer cells in vitro. The expression of TLR9 mRNA and protein in SiHa, Hela and C33A cells was detected by RT-PCR and Western blotting. Real-time PCR was used to examine the TLR9 expression changes induced by CpG. Chemosensitivity of the cervical cancer cells to cisplatin (DDP) was measured by MTT. It was observed that the expression of TLR9 mRNA and protein was increased gradually in SiHa (HPV16+), Hela (HPV18+) and C33A (HPV−) cells. Low doses of CpG increased the TLR9 expression only in C33A (HPV−) cells, but not in SiHa (HPV16+) and Hela (HPV18+) cells. Furthermore, low dose of CpG significantly increased the sensitivity of C33A (HPV−) cells, but not that of SiHa (HPV16+) and Hela (HPV18+) cells. These results indicated that TLR9 may serve as a protective agent in HPV negative cervical cancer cells. It was concluded that TLR9 could improve the sensitivity to DDP in HPV negative cervical cancer cells and might represent a potential therapeutic option in clinical practice.Inflammation and infection play an important role in the pathogenesis of many cancers. Toll-like receptors (TLRs) are a class of pattern recognition receptors that recognize conserved components of microbes and trigger the immune response against invading microorganisms. Toll-like receptor 9 (TLR9) recognizes non-methylated cytosine-phosphateguanosine (CpG) DNA sequences which are the surrogate for viral DNA. TLR9 may react to tumor development and progression during chronic inflammation that involves the tumor microenvironment. In order to study the role of TLR9 in cervical cancer, we analyzed the TLR9 expression in different types of HPV infection cervical cancer cells. Then we detected if CpG sequences influenced the TLR9 expression and the sensitivity to cisplatin (DDP) of these cervical cancer cells in vitro. The expression of TLR9 mRNA and protein in SiHa, Hela and C33A cells was detected by RT-PCR and Western blotting. Real-time PCR was used to examine the TLR9 expression changes induced by CpG. Chemosensitivity of the cervical cancer cells to cisplatin (DDP) was measured by MTT. It was observed that the expression of TLR9 mRNA and protein was increased gradually in SiHa (HPV16+), Hela (HPV18+) and C33A (HPV−) cells. Low doses of CpG increased the TLR9 expression only in C33A (HPV−) cells, but not in SiHa (HPV16+) and Hela (HPV18+) cells. Furthermore, low dose of CpG significantly increased the sensitivity of C33A (HPV−) cells, but not that of SiHa (HPV16+) and Hela (HPV18+) cells. These results indicated that TLR9 may serve as a protective agent in HPV negative cervical cancer cells. It was concluded that TLR9 could improve the sensitivity to DDP in HPV negative cervical cancer cells and might represent a potential therapeutic option in clinical practice.

HPV16 E5 peptide vaccine in treatment of cervical cancer in vitro and in vivo

SummaryHuman papillomavirus (HPV)-induced cervical cancer is the second most common cancer among women worldwide. Despite the encouraging development of the preventive vaccine for HPV, a vaccine for both prevention and therapy or pre-cancerous lesions remains in high priority. Thus far, most of the HPV therapeutic vaccines are focused on HPV E6 and E7 oncogene. However these vaccines could not completely eradicate the lesions. Recently, HPV E5, which is considered as an oncogene, is getting more and more attention. In this study, we predicted the epitopes of HPV16 E5 by bioinformatics as candidate peptide, then, evaluated the efficacy and chose an effective one to do the further test. To evaluate the effect of vaccine, rTC-1 (TC-1 cells infected by rAAV-HPV16E5) served as cell tumor model and rTC-1 loading mice as an ectopic tumor model. We prepared vaccine by muscle injection. The vaccine effects were determined by evaluating the function of tumor-specific T cells by cell proliferation assay and ELISPOT, calculating the tumor volume in mice and estimating the survival time of mice. Our in vitro and in vivo studies revealed that injection of E5 peptide+CpG resulted in strong cell-mediated immunity (CMI) and protected mice from tumor growth, meanwhile, prolonged the survival time after tumor cell loading. This study provides new insights into HPV16 E5 as a possible target on the therapeutic strategies about cervical cancer.Human papillomavirus (HPV)-induced cervical cancer is the second most common cancer among women worldwide. Despite the encouraging development of the preventive vaccine for HPV, a vaccine for both prevention and therapy or pre-cancerous lesions remains in high priority. Thus far, most of the HPV therapeutic vaccines are focused on HPV E6 and E7 oncogene. However these vaccines could not completely eradicate the lesions. Recently, HPV E5, which is considered as an oncogene, is getting more and more attention. In this study, we predicted the epitopes of HPV16 E5 by bioinformatics as candidate peptide, then, evaluated the efficacy and chose an effective one to do the further test. To evaluate the effect of vaccine, rTC-1 (TC-1 cells infected by rAAV-HPV16E5) served as cell tumor model and rTC-1 loading mice as an ectopic tumor model. We prepared vaccine by muscle injection. The vaccine effects were determined by evaluating the function of tumor-specific T cells by cell proliferation assay and ELISPOT, calculating the tumor volume in mice and estimating the survival time of mice. Our in vitro and in vivo studies revealed that injection of E5 peptide+CpG resulted in strong cell-mediated immunity (CMI) and protected mice from tumor growth, meanwhile, prolonged the survival time after tumor cell loading. This study provides new insights into HPV16 E5 as a possible target on the therapeutic strategies about cervical cancer.

Primary yolk sac tumor of the endometrium

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Correlation between physical status of human papilloma virus and cervical carcinogenesis

The prevalence of human papilloma virus (HPV)-16 in patients with cervical cancer, the physical status of HPV-16 in patients with cervical lesions, and the role of HPV-16 integration in cervical carcinogenesis were investigated. HPV genotyping was performed by using PCR approach with the primer GP5+/GP6+ and type-specific primer on biopsy specimens taken operatively from 198 women. Multiple PCR was done to detect physical status of HPV-16 in a series of cervical liquid-based cytology samples and biopsy specimens obtained from different cervical lesions with HPV-16 infection, including 112 specimens with cervical cancer, 151 specimens with CIN I, 246 specimens with CIN and 120 specimens with CINIII. The results showed that there were 112 cervical cancer samples (56.57% of total cervical cancer patients) with HPV-16 infection. The frequency of HPV-16 pure integration was 65.18% (73/112), 56.57% (47/120), 23.58% (58/246) and 7.95% (12/151) in cervical cancer, CINIII, CINII and CINI patients respectively. In situ hybridization was performed on some paraffin-embedded sections of CINII, CINIII and cervical cancer to verify the physical status of HPV-16 infection. Significant difference was observed between cervical cancer and CIN I, CINII, CINIII in the frequency of HPV-16 integration (P<0.01). It is suggested that HPV-16 is the most prevalent type and is associated with cervical cancer. In the case of HPV-16 infection there are close associations between the severity of cervical lesions and the frequency of HPV-16 integration. The application of testing HPV genotyping and physical status based on detection of HC-II HPV DNA would be in favor of predicting the prognosis of cervical precancerosis and enhancing the screening accuracy of cervical cancer.SummaryThe prevalence of human papilloma virus (HPV)-16 in patients with cervical cancer, the physical status of HPV-16 in patients with cervical lesions, and the role of HPV-16 integration in cervical carcinogenesis were investigated. HPV genotyping was performed by using PCR approach with the primer GP5+/GP6+ and type-specific primer on biopsy specimens taken operatively from 198 women. Multiple PCR was done to detect physical status of HPV-16 in a series of cervical liquid-based cytology samples and biopsy specimens obtained from different cervical lesions with HPV-16 infection, including 112 specimens with cervical cancer, 151 specimens with CIN I, 246 specimens with CIN and 120 specimens with CINIII. The results showed that there were 112 cervical cancer samples (56.57% of total cervical cancer patients) with HPV-16 infection. The frequency of HPV-16 pure integration was 65.18% (73/112), 56.57% (47/120), 23.58% (58/246) and 7.95% (12/151) in cervical cancer, CINIII, CINII and CINI patients respectively. In situ hybridization was performed on some paraffin-embedded sections of CINII, CINIII and cervical cancer to verify the physical status of HPV-16 infection. Significant difference was observed between cervical cancer and CIN I, CINII, CINIII in the frequency of HPV-16 integration (P<0.01). It is suggested that HPV-16 is the most prevalent type and is associated with cervical cancer. In the case of HPV-16 infection there are close associations between the severity of cervical lesions and the frequency of HPV-16 integration. The application of testing HPV genotyping and physical status based on detection of HC-II HPV DNA would be in favor of predicting the prognosis of cervical precancerosis and enhancing the screening accuracy of cervical cancer.

Gene co-expression network reveals shared modules predictive of stage and grade in serous ovarian cancers

Serous ovarian cancer (SOC) is the most lethal gynecological cancer. Clinical studies have revealed an association between tumor stage and grade and clinical prognosis. Identification of meaningful clusters of co-expressed genes or representative biomarkers related to stage or grade may help to reveal mechanisms of tumorigenesis and cancer development, and aid in predicting SOC patient prognosis. We therefore performed a weighted gene co-expression network analysis (WGCNA) and calculated module-trait correlations based on three public microarray datasets (GSE26193, GSE9891, and TCGA), which included 788 samples and 10402 genes. We detected four modules related to one or more clinical features significantly shared across all modeling datasets, and identified one stage-associated module and one grade-associated module. Our analysis showed that MMP2, COL3A1, COL1A2, FBN1, COL5A1, COL5A2, and AEBP1 are top hub genes related to stage, while CDK1, BUB1, BUB1B, BIRC5, AURKB, CENPA, and CDC20 are top hub genes related to grade. Gene and pathway enrichment analyses of the regulatory networks involving hub genes suggest that extracellular matrix interactions and mitotic signaling pathways are crucial determinants of tumor stage and grade. The relationships between gene expression modules and tumor stage or grade were validated in five independent datasets. These results could potentially be developed into a more objective scoring system to improve prediction of SOC outcomes.