| Breast cancer is one of the most common malignancies in women worldwhile, and its incidence rate is still rising. In developped countries such as America, the incidence rate of breast cancer occupies the first place of the malignancies in women, accounting for30-32percent. The same situation happens in some developped cities in China. In that case, breast cancer has been a serious disease threatening the physical and mental health of women all over the world.As we know, breast cancer is an incidence concerned with multi-genes and multi-stages, and many genes have been changed in order in the progress of the normal mammary epithelial cells transferring into maliganance cells. Breast cancer is associated with the combination of both environmental factors and genetic factors, and even in the same backgroud of environmental factors, only a small portion of people have breast cancer, implying that differrent genetic background effect the breast cancer susceptibility of individuals. So far, the most popular breast cancer susceptibility genes are BRCA1and BRCA2, which have been reported to increase the risk of breast cancer in the BRCA1and BRCA2mutant carriers. However, BRCA1and BRCA2only accout for5-10percent of breast cancer overall, assuming that there are more genes except BRCA1and BRCA2associating with the susceptibility of breast cancer. In recent years, GWAS has become a powerful tool to detect the low-penetrance and high-frequency loci, and GWAS has identified a large number of SNPs within several low-penetrance genes, such as FGFR2、LSP1、 MAP3K1、TGFB1、TCX3and etc.VARS2is located in HLA region, encoding the synthesis of ValRS. It has been reproted in abroad that VARS2might be associated with lung cancer and some autoimmune diseases, while another report shows the variation of this gene could associate with the prognosis of early breast cancer. FGFR2is one of the receptor tyrosine kinases(RTKs), which plays an important role in cell proliferation, differentation, angiogenesis, skeletal development and other progress in human growth and development. It has been reported that FGFR2is associated with a lot of diseases, especially the relation between the tumor and FGFR2. GWAS has identified that FGFR2is the susceptibility gene inreasing the risk of breast cancer, and particularly highlight the intron2that harbors eight single nucleotide polymorphisms,including rs35054928, rs2981578, rs2912778, rs2912781, rs35393331, rs10736303, rs7895676, rs33971856.Besides, the alternative splicing of FGFR2has become an issue in reserch recently. FGFR2IIIB and FGFR2IIIC are the most important splicing variants, which are produced by the alternative splicing of the3rd Ig-like loop regions. It has been reported that a FGFR2IIIB to IIIC switch is related to increased invasiveness in bladder cancers; the higher expression of FGFR2IIIC than FGFR2IIIB is found in metastatic breast cancer. Therefore, we expect the expression of FGFR2IIIB and FGFR2IIIC is related to the progress of breast cancer.Our study is divided into two parts:the aim of the first part is to explore the relationship between the SNPs in VARS2and FGFR2and the breast cancer susceptibility in Chinese female breast cancer patients in a case-control study, using the Sequenom MassARRA(?)-IPLEX platform, and stratified analysis was performed based on the Immunohistochemical results of estrogen receptor (ER) and progesterone receptor (PR); the aim of the second part is to investigate the relationship between the splicing variants and breast cancer in case-control study, using the qPCR technique, and further study was performed with different clinical pathological data.PART I Association of SNPs in VARS2gene and FGFR2gene with susceptibility of sporadic breast cancer in Chinese womenAssociation of SNP in VARS2gene with susceptibility of breast cancer[AIM] to investigate the correlation of single nucleotide polymorphisms in VARS2(rs2249464) with susceptibility of sporadic breast cancer in Guangdong women of Han Nationality.[METHOD] A case-control study consisting of216breast cancer patients and216healthy controls was performed using the Sequenom MassARRAY(?)-IPLEX platform and MALDI-TOF-MS technique. Association was analyzed by Chi-square and unconditional logistic regression,and further stratified analysis was performed based on the Immunohistochemical results of estrogen receptor (ER) and progesterone receptor (PR).[RESULT] There was a significant difference of the frequencies between the genotype of rs2249464(VARS2) in the case group and the control group (P<0.05);The frequencies of genotype were not significantly different in the ER(-) and ER(+) groups(P>0.05);However, there was a significant difference of the frequencies between the PR(-) and PR(+) groups(P<0.05).[CONCLUSION] the polymorphism of rs2249464in VARS2might associate with susceptibility of sporadic breast cancer in Guangdong women of Han Nationality, and those breast cancer patients carrying T/T genotype could be more likely to have a PR(-) breast cancer.Association of SNPs in FGFR2gene with susceptibility of breast cancer in Chinese women[AIM] to investigate the correlation of single nucleotide polymorphisms in FGFR2, including Rs1078806, Rs2420946, Rs2981579,Rs7895676and Rs1219648,with susceptibility of sporadic breast cancer in Chinese women.[METHOD] A case-control study consisting of845breast cancer patients and882healthy controls was performed using the Sequenom MassARRAY(?)-IPLEX platform and MALDI-TOF-MS technique.Association was analyzed by Chi-square and unconditional logistic regression,and further stratified analysis was performed based on the Immunohistochemical results of estrogen receptor (ER) and progesterone receptor (PR).[RESULT](1)There was not a significant difference of the frequencies between the genotype of Rs1078806in the case group and the control group (P>0.05);The frequencies of genotype were not significantly different in the ER(-) and ER(+) groups(P>0.05);However, there was a significant difference of the frequencies between the PR(-) and PR(+) groups(P<0.05).(2)There was a significant difference of the frequencies between the genotype of Rs2420946in the case group and the control group (P<0.05);The frequencies of genotype were significantly different in the ER(-) and ER(+) groups(P<0.05); And,there was a significant difference of the frequencies between the PR(-) and PR(+) groups(P<0.05).(3)There was a significant difference of the frequencies between the genotype of Rs2981579in the case group and the control group (P<0.05);The frequencies of genotype were significantly different in the ER(-) and ER(+) groups(P<0.05); And,there was a significant difference of the frequencies between the PR(-) and PR(+) groups(P<0.05).(4)Rs7895676and Rs1219648were calculated to be not in equilibrium(P<0.05).[CONCLUSION](1) the polymorphism of Rs2420946'Rs2981579in FGFR2might associate with susceptibility of sporadic breast cancer in Chinese women, and T/T genotype in both SNPs increase the risk of breast cancer.(2) the polymorphism of Rs1078806in FGFR2gene might relate to the status of PR in breast cancer.(3)the polymorphism of Rs2420946'Rs2981579in FGFR2might associate with the status of ER, and those breast cancer patients carrying T/T genotype could be more likely to have a ER positive breast cancer.PRAT II Association between splicing variants and breast cancer[AIM] to explore the relationship between the splicing variants of FGFR2gene and breast cancer, and to estimate the corelation of he FGFR2splicing variants and the clinical pathological data.[METHOD]35cases of breast cancer tissues and adjacent tisseus were collected from Breast cancer patients who visited breast center in Nanfang Hospital. To differentiate the expression of FGFR2IIIB and FGFR2IIIC using restriction enzyme AVAI and EcoR V to cut the specific fragment including exon6-9in FGFR2, then observe the characteristic band in the ultraviolet transilluminator after agarose gel electrophoresis; to detect the absolute quantification of FGFR2IIIB and FGFR2IIIC both in the breast cancer tissues and adjacent tissues, using the SYBR real-time PCR technique. Comparison of FGFR2IIIB and FGFR2IIIC expression between the breast cancer tissues and adjacent tissues was analyzed by non-parametric test, and further comparison under different clinical pathological data was analyzed by non-parametric test.[RESULTS]1. Characteristic fragments(70bp and230bp) were observed after the restriction enzyme AVAI digestion of FGFR2IIIB, and characteristic fragments(180bpand120bp) after EcoR V digestion of FGFR2IIIC. Out of15cases of breast cancer tissues, FGFR2IIIB were detected in all15breast cancer tissues, and FGFR2IIIC were detected in only7breast cancer tissues.2.(1)expression of FGFR2IIIB and FGFR2IIIC in breast cancer tissues and adjacent tissues seperately:there was no significant difference of FGFR2IIIB and FGFR2IIIC expression between the case group and the control group seperately (P>0.05); However, the expression between FGFR2IIIB and FGFR2IIIC had significant difference in breast cancer tissues and/or in adjacent tissues, the expression of FGFR2IIIB was higher than FGFR2IIIC (P<0.05).(2)there was a significant difference of expression of FGFR2IIIB and FGFR2IIIC between the different age groups in case group (P<0.05), the expression of FGFR2IIIB and FGFR2IIIC was higher in the younger group(age<50) than the older group(age≥50); and there was not a significant difference between the expression of FGFR2IIIB and FGFR2IIIC under the age group(P>0.05).(3)there was a significant difference of expression of FGFR2IIIB and FGFR2IIIC between the different clinical stage groups in the breast cancer group (P<0.05), the expression of FGFR2IIIB and FGFR2IIIC was higher in the later stages(III, IV) than the ealier stages(0,I, II); and there was not a significant difference between the expression of FGFR2IIIB and FGFR2IIIC under the clinical stage group(P>0.05).(4) there was not a significant difference of expression of FGFR2IIIB and FGFR2IIIC between the different lymphatic metastasis groups in case group(P>0.05), and there was not a significant difference between the expression of FGFR2IIIB and FGFR2IIIC under the lymphatic metastasis group(P>0.05).(5)there were not significant differences of expression of FGFR2IIIB and FGFR2IIIC between the different ER, PR, HER2, and molecular type groups in breast cancer tissues(P>0.05), and also there were not significant differences between the expression of FGFR2IIIB and FGFR2IIIC under the these groups(P>0.05).[CONCLUSIONS]1.The expression between the FGFR2IIIB and FGFR2IIIC was different in both breast cancer tissues and adjacent tissues, and FGFR2IIIB expression is higher.2. FGFR2IIIB and FGFR2IIIC expression are higher in the youger breast cancer patients.3. FGFR2IIIB and FGFR2IIIC expression are higher in the later clinical stages.4. Above all, FGFR2IIIB and FGFR2IIIC expression level might be higher in the higher degree malignancy. |
PDF Full Text Request