Jingjing Ma

Meta-analysis on the association between non-steroidal anti-inflammatory drug use and ovarian cancer

AIM Animal and in vitro studies suggest that the use of non‐steroidal anti‐inflammatory drugs (NSAIDs) may be associated with reduced risk for ovarian cancer. However, results from these studies have been inconsistent. The aim of our study was to review and summarize the evidence provided by longitudinal studies on the association between NSAID use and ovarian cancer risk.

Hypoxia-induced factor-1 alpha upregulates vascular endothelial growth factor C to promote lymphangiogenesis and angiogenesis in breast cancer patients

Hypoxia-induced factor-1 alpha (HIF-1α) affects many effector molecules and regulates tumor lymphangiogenesis and angiogenesis during hypoxia. The aim of this study was to investigate the role of HIF-1α in the regulation of vascular endothelial growth factor C (VEGF-C) expression and its effect on lymphangiogenesis and angiogenesis in breast cancer. Lymphatic vessel density (LVD), microvessel density (MVD) and the expressions of HIF-1α and VEGF-C proteins were evaluated by immunohistochemistry in 75 breast cancer samples. There was a significant correlation between HIF-1α and VEGF-C (P = 0.014, r = 0.273, Spearmans coefficient of correlation). HIF-1α and VEGF-C overexpression was significantly correlated with higher LVD (P = 0.003 and P = 0.017, respectively), regional lymph nodal involvement (P = 0.002 and P = 0.004, respectively) and advanced tumor, node, metastasis (TNM) classification (P = 0.001 and P = 0.01, respectively). Higher MVD was observed in the group expressing higher levels of HIF-1α and VEGF-C (P = 0.033 and P = 0.037, respectively). Univariate analysis showed shorter survival time in patients expressing higher levels of HIF-1α and VEGF-C. HIF-1α was also found to be an independent prognostic factor of overall survival in multivariate analysis. The results suggest that HIF-1α may affect VEGF-C expression, thus acting as a crucial regulator of lymphangiogenesis and angiogenesis in breast cancer. This study highlights promising potential of HIF-1α as a therapeutic target against tumor lymph node metastasis.

Perfluorooctanoic acid stimulates breast cancer cells invasion and up-regulates matrix metalloproteinase-2/-9 expression mediated by activating NF-κB.

Perfluorooctanoic acid (PFOA) is widely used because of its stain-resistant and water-repellant properties. This study aimed to explore the molecular mechanisms undergoing the stimulation effects of PFOA on cancer cell invasion and matrix metalloproteinases (MMPs) expression. Trans-well filter assay showed that PFOA exposure (≥5 nM) evidently enhanced the invasion ability of the breast cancer cells MDA-MB-231. Luciferase reporter assay, quantitative real-time PCR, western blotting and gelatin zymography consistently demonstrated that mRNA and protein levels of MMP-2/-9 were increased in the cells after PFOA treatment (P<0.05 each). Western blotting revealed that PFOA could activate nuclear factor kappaB (NF-κB) by accelerating NF-κB translocation into the nucleus. Furthermore, addition of NF-κB inhibitor in culture medium could suppress the breast cancer cells invasiveness enhancement and MMP-2/-9 overexpression. This study indicates that PFOA can stimulate breast cancer cells invasion and up-regulate matrix metalloproteinase-2/-9 expression mediated by activating NF-κB, which deserves more environmental health concerns.

Exposure to bisphosphonates and risk of colorectal cancer.

Animal and in vitro studies suggest that the use of bisphosphonates (BPs) may be associated with reduced risk for colorectal cancer (CRC). However, results from these studies have been inconsistent. The aim of our study was to review and summarize the evidence provided by longitudinal studies on the association between BP use and CRC risk A comprehensive literature search for articles published up to October 2012 was performed. Prior to performing a meta-analysis, the studies were evaluated for publication bias and heterogeneity. Relative risks (RRs) or odds ratios were calculated. Six reports (four case-control studies and two cohort studies) published between 2010 and 2012 were identified. There was evidence of an association between any use of BPs and CRC risk using a fixed-effects model (RR = 0.80, 95% confidence interval = 0.74, 0.85) and a random-effects model (RR = 0.80, 95% confidence interval = 0.71, 0.90). However, we did not observe any evidence of a trend with increasing duration of use. Our findings indicate that there is evidence of an association between any use of BP and reduced CRC risk. However, this subject deserves further investigation.

Identification and characterization of microRNAs expressed in human breast cancer chemo-resistant MCF-7/Adr cells by Solexa deep-sequencing technology

BACKGROUND/AIM Breast cancer is the most common type of tumor in female and chemoresistance has been a major clinical obstacle to the treatment in clinical patients. miRNA was one of the factors demonstrated to play certain roles in chemoesistance in breast cancer. In this study, we exploited Solexa deep sequencing technology to identify differentially expressed miRNA from samples in vitro, trying to find novel relationship between miRNA and chemoresistance in breast cancer. METHODS The human breast cancer MCF-7 cell line was pulse-selected with doxorubicin (10 pulses, once a week for 4h, with 1μM doxorubicin) to generate MCF-7/Adr cells. Total RNA was extracted from the treated and untreated MCF-7 cells and subsequently subjected to real time PCR. Two small RNA libraries of MCF7NON and MCF7ADR were established to record the Solexa sequencing results of the PCR products above. All the sequencing results were verified by Stem-loop real-time PCR. GO annotation and KEGG analysis program were exploited to enrich the differentially expressed miRNAs. RESULTS The results showed that 214,822 and 378,597 reads were mapped in the MCF7ADR and MCF7NON libraries when aligned to hairpin structure respectively. Meanwhile, 1323 and 520 reads were mapped when aligned to mature sequences. In addition, 310 known mature miRNAs were coexpressed in both libraries. Comparing the MCF7ADR group to the MCF7NON group, 18 miRNAs were significantly differentially expressed. GO annotation and KEGG analysis showed that the target genes were enriched in regulation of transcription and development as well as Wnt signaling pathway, MAPK signaling pathway and TGF-ß signaling pathway. CONCLUSION The results proved that the Solexa deep sequencing was a powerful and reliable platform to analyze small RNAs. And further investigation should be conducted for the biological process and pathways that have been identified and more efforts should be made to research the mechanism of chemoresistance in breast cancer.

SPARC inhibits breast cancer bone metastasis and may be a clinical therapeutic target

Breast cancer is one of the most common types of cancer in females worldwide, and metastasis to bone is an important characteristic of malignancy. The present study aimed to investigate the molecular mechanism of breast cancer to bone metastasis of secreted protein acidic and rich in cysteine (SPARC). Immunohistochemistry was performed to examine the expression of SPARC in primary breast tumors and bone metastatic foci. Western blotting and reverse transcription-quantitative polymerase chain reaction were performed to detect the expression level of SPARC in several types of breast cancer cell. A Transwell filter assay was used to assess the effect of SPARC on breast cancer cell invasion ability, and an osteoblast differentiation assay was employed to analyze the effect of SPARC on the differentiation ability of mesenchymal stem cells. Clinical data revealed that decreased stromal SPARC expression is associated with breast cancer to bone metastasis. Gain- and loss-of-function studies reveal that SPARC inhibits the migration and invasion of breast cancer cells, and suppresses osteoclast activation in the breast cancer microenvironment. SPARC serves an important role in breast cancer bone metastasis and may be a promising therapeutic target for the treatment of breast cancer bone metastasis.

Benzotriazole Enhances Cell Invasive Potency in Endometrial Carcinoma Through CTBP1-Mediated Epithelial-Mesenchymal Transition

Background/Aims: Benzotriazole (BTR) and its derivatives, such as intermediates and UV stabilizers, are important man-made organic chemicals found in everyday life that have been recently identified as environmental toxins and a threat to female reproductive health. Previous studies have shown that BTR could act as a carcinogen by mimicking estrogen. Environmental estrogen mimics could promote the initiation and development of female cancers, such as endometrial carcinoma, a type of estrogenic-sensitive malignancy. However, there is little information on the relationship between BTR and endometrial carcinoma. In this study, we aimed to demonstrate the biological function of BTR in endometrial carcinoma and explored the underlying mechanism. Methods: The CCK-8 assay was performed to detect cell viability; transwell-filter assay was used to assess cell invasion; gene microarray analysis was employed to determine gene expression patterns in response to BTR treatment; western blotting and quantitative reverse transcription polymerase chain reaction (qRT-PCR) were carried out to detect the expression levels of BTR-related genes. Results: Our data showed that BTR could induce the invasion and migration of endometrial carcinoma cells (Ishikawa and HEC-1-B). In addition, BTR increased the expression level of CTBP1, which could enhance the epithelial-mesenchymal transition (EMT) in cancer cells. Moreover, CTBP1 silencing reversed the effect of BTR on EMT progression in endometrial carcinoma cells. Conclusion: This study indicates that BTR could act as a carcinogen to promote the development of endometrial carcinoma mainly through CTBP1-mediated EMT, which deserves more attention.

Comprehensive profiling of biological processes reveals two major prognostic subtypes in breast cancer.

Heterogeneity is the major obstacle to breast cancer target therapy. Classification of breast cancer with significant biological process may reduce the influence of heterogeneity of intrinsic tumor. We used survival analysis to filter 95 gene sets and classify 638 breast cancer samples into two subtypes based on those gene sets associated with prognosis. Clinical outcome of two subtypes were evaluated with disease-free survival, distant metastasis-free survival, and overall survival levels in three databases and ER+, PR+ HER2+, and TNBC groups. We established a novel classification with 95 prognostic gene sets. In the training and validation cohorts, the subtype 1 was characterized by significant gene sets associated with regulation of metabolic process and enzyme activity and predicted obviously improved clinical outcome than subtype 2, which was enriched by tumor cell division, mitosis, and cell cycle-related gene sets (P < 0.05). When evaluated prognostic impact of subtypes in ER+, PR+ HER2+, and TNBC groups, we found that patients in subtype 1 showed better prognosis in ER+ and PR+ groups (P < 0.05) but had no difference from prognosis of subtype 2 in HER2+ and TNBC groups. These findings may have implications in understanding of breast cancer and filtering effective therapeutic strategies for targeted therapy.