A Correlation Analysis Of The Relationship Between RASSF1A Gene Promoter Methylation And Cancer Susceptibility/Prognosis

Purpose:RASSF1A (Ras association domain family 1 isoform A) is an important tumor suppressor. It can maintain the stability of microtubules, promoting apoptosis, control cell cycle, etc.Current studies suggested that RASSF1A gene was lower expression in cancer cells, which due to the results of DNA promoter methylation. This study through using bioinformatics methods and meta analysis to reaserch the relationship between RASSF1A gene promoter methylation and cancer susceptibility/prognosis, and to explore the value of RASSF1A promoter methylation in cancer diagnosis.Methods:We download methylation data and clinical data of 33 cancer types (acute myeloid leukemia, adrenocortical carcinoma, bladder urothelial carcinoma, brain lower grade glioma, breast invasive carcinoma, cervical squamous cell carcinoma and endocervical adenocarcinoma, cholangiocarcinoma, colon adenocarcinoma, esophageal carcinoma, glioblastoma multiforme, head and neck squamous cell carcinoma, kidney chromophobe, kidney renal clear cell carcinoma, kidney renal papillary cell carcinoma, liver hepatocellular carcinoma, lung adenocarcinoma, lung squamous cell carcinoma, lymphoid neoplasm diffuse large B-cell lymphoma, mesothelioma, ovarian serous cystadenocarcinoma, pancreatic adenocarcinoma, pheochromocytoma and paraganglioma, prostate adenocarcinoma, rectum adenocarcinoma, sarcoma, skin cutaneous melanoma, stomach adenocarcinoma, testicular germ cell tumors, thymoma, thyroid carcinoma, uterine carcinosarcoma, uterine corpus endometrioid carcinoma, uveal melanoma), whihc from Level 1 by HumanMethylation450 BeadChip (Illumina) platform of TCGA (The Cancer Gene Atlas). Meanwhile, we used R software to analysis the relationship bewteen RASSF1A gene promoter methylation and susceptibility/prognosis of the 33 cancer types. In addition, we used meta-analysis method, according to the literature retrieval standard of Cochrane collaboration. We conducted a literature search (up to and including 31 th December 2015) of computerized databases, including PubMed, Cochrane Library, PubMed, Medline, Embase,Web of Science, SciFinder, Google Scholar, China National Knowledge Infrastructure (CNKI), Wangfang database, Weipu database, for articles published in both English and Chinese. The literature about the relations of RASSF1A gene promoter methylation and cancer in case-control were selected. Ultimately, the eligible studies was used by R software (meta package) for meta analysis.Results:We used the DNA methylation data and clinical data from TCGA project, analyzed the relationship between RASSF1A gene promoter methylation and susceptibility of 15 cancer types, as well as 28 cancer types prognosis. We found that the level methylation of RASSF1A gene promoter methylation and bladder urothelial carcinoma risk (OR=33.76, p<0.0001), breast invasive carcinoma risk (OR=22.92, p<0.0001), colon adenocarcinoma risk (OR=2.38, p<0.0001), esophageal carcinoma risk (OR=9.71, p<0.0001), head and neck squamous cell carcinoma risk (OR=2.62, p＜0.0001), kidney renal clear cell carcinoma risk (OR=13.26, p＜0.0001), kidney renal papillary cell carcinoma risk (OR= 109.00, p<0.0001), liver hepatocellular carcinoma risk (OR=24.92, p<0.0001), lung adenocarcinoma risk (OR=36.56, p＜0.0001), lung squamous cell carcinoma risk (OR=56.95, p<0.0001), pancreatic adenocarcinoma risk (OR=6.64, p＜0.0001), prostate adenocarcinoma risk (OR=463.67, p＜0.0001), adenocarcinoma risk (OR=1.25, p＜0.0001), Thyroid carcinoma risk (OR=750.55, p＜0.0001), uterine corpus endometrioid carcinoma risk (OR=27.04, p＜0.0001) were significantly higher than normal control, In addition, we also found that the overall survival (OS) (HR=1.83, p=0.04) and disease free survival (DFS) (HR=1.97, p=0.037) of bladder urothelial carcinoma patients without RASSFIA gene promoter methylation were longer than those with RASSF1A gene promoter methylation, the OS (HR=5.84, p=0.009) and DFS (HR=3.55, p=0.01) of thymoma patients without RASSFIA gene promoter methylation were longer than those with RASSF1A gene promoter methylation, the DFS (HR=2.25, p=0.006) of colon cancer patients without RASSFIA gene promoter methylation were longer than those with RASSFIA gene promoter methylation, the OS (HR=1.66, p=0.006) of head and neck squamous cell carcinoma patients without RASSFIA gene promoter methylation were longer than those with RASSFIA gene promoter methylation. Meanwhile, there were a statistical significant relationship between RASSFIA gene promoter methylation and lung squamous carcinoma DFS (HR=0.51, p=0.003), prostatic adenocarcinoma DFS (HR=0.15, p=0.002). However, there was no significant relationship in RASSFIA gene promoter methylation and other cancers DFS/OS.For meta-analysis,338 articles about cancers susceptibility which were included in colorectal cancer, lung cancer, cancers of the female reproductive organs (cervical cancer, endometrial carcinoma of uterus, ovarian cancer, vaginal carcinoma), liver cancer, thyroid cancer, cancers of the male reproductive organs (carcinoma of penis, testicular cancer, prostatic cancer), bladder cancer, skin cancer, breast cancer, tumours of the nervous system, kidney cancer, oesophageal cancer, head and neck cancers, stomach cancer, haematopoietic and lymphoid malignancies, pancreatic cancer, after we screened 3287 potentially relevant articles for inclusion, on the basis of title, abstract and full text. In addition,31 aticles about cancers prognosis which were included in lung cancerliver cancer, breast cancer, bladder cancer. We found that there were a statistical significant relationship between RASSF1A gene promoter methylation and bladder cancer OS (HR=1.42, p=0.0003), breast cancer OS (HR=1.55, p=0.0008) and DFS (HR=1.50, p＜0.0001).Meta analysis method was used to further combine TCGA results and the result of collected literature.We found that there was a significant relationship in RASSF1A gene promoter methylation and colorectal cancer risk (OR=6.52, p<0.0001), lung cancer risk (OR=16.75, p＜0.0001), cancers of the female reproductive organs risk (OR=10.00, p＜0.0001), liver cancer risk (OR=18.30, p＜0.0001), thyroid cancer risk (OR=9.78, p＜0.0001), cancers of the male reproductive organs risk (OR=12.59, p＜0.0001), bladder cancer risk (OR=21.51, p＜0.0001), breast cancer risk (OR=20.30, p＜0.0001), kidney cancer risk (OR=15.02, p＜0.0001), oesophageal cancer risk (OR=11.91, p＜0.0001), head and neck cancer risk (OR=24.69, p＜0.0001), pancreatic cancer risk (OR=3.47, p=0.0012). We also found that the survival rate of bladder cancer OS (HR=1.37, p＜0.0001), lung cancer OS (HR=1.18, p=0.0073), breast cancer OS (HR=1.42, p=0.0019) and DFS (HR=1.44, p＜0.0001), was lower in the status of RASSF1A gene promoter methylation.Conclusion:There was a significant association was identified between methylation of the RASSF1A gene promoter and the risk of colorectal cancer, lung cancer, cancers of the female reproductive organs, liver cancer, thyroid cancer, cancers of the male reproductive organs, bladder cancer, breast cancer, kidney cancer, oesophageal cancer, head and neck cancers, pancreatic cancer, as well as prognosis of bladder cancer, lung cancer, breast cancer. RASSF1A gene promoter methylation will be a biomarker for predict the incidence of the above 12 cancer types, and it will be a potential prognostic marker for bladder cancer, lung cancer, breast cancer. The clinical value of RASSF1A gene promoter methylation is remains to be further confirmed good high quality research.