SEMA3B And SEMA3F Genes Expression In Primary Lung And Esophageal Carcinomas And Its Clinical Significances

Tumorigenesis results from the abnormal regulation of genes involved in cellular homeostasis. One mechanism involve the alteration in gene expression or mutation of tumor suppressor genes, which are recessive genes where mutation results of loss of function. There are several regions within the human genome that when altered, lead to uncontrolled cell proliferation. The short arm of chromosome 3 has been shown to exhibit high loss of heterozygosity (LOH) in several types of cancer including ovarian, kidney, lung, and testicular cancers. In particular, overlapping homozygous deletions in lung cancers have been identified in region 3p21.3 where already 19genes were found. In particular the 3p21.3 region exhibits a high LOH in lung, breast, stomach and ovarian carcinomas suggesting the existence of a putative tumor suppressor gene within this region. In small cell lung cancer, >90% of the tumors exhibits LOH at this site. Two Class III Semaphorin genes SEMA3B and SEMA3F are ones of them. A few articles converge about mRNA expression and suppressor mechanism on tumor cell line, but up to now, there is no publication about SEMA3B and SEMA3F mRNA expression and their tumor suppressor function mechanism in lung and esophageal carcinoma tissue. But the association between the expression of this two SEMA and their clinicopathologic characters was still unexplored in primary lung cancer. The 3p LOH in esophageal carcinoma has been established but there is no publication yet about SEMA3B and SEMA3F in esophageal carcinoma.In this study, we firstly used the RT-PCR method to evaluate the transcription expression of SEMA3B and SEMA3F in 52 cases of Chinese lung cancer tissues and adjacent normal tissues. The result showed that, the SEMA3B and SEMA3F transcription were identified in all non-cancer tissues but was not found in 53.2%(27/52) and 55.2(29/52) carcinoma tissues (p<0.001). Loss of SEMA3B expression was significantly high in patients with positive lymph node metastasis 64.3% (18/28) compared with those without lymph node metastasis 29.2 %( 7/24) (p<0.05). The rate of loss of SEMA3B mRNA expression was correlated with TNM stage (p<0.05), which was more frequently observed in those with advanced tumor stage. There is no significant association of abnormal expression with histological type, differentiation grade stage of tumors or age, sex, and smoking index. SEMA3B and SEMA3F expression loss respectively were 48.1% (25/52) and 44.2%(23/52) with no significant difference in rate but with different pattern: the cumulative incidence of expression losswas69.231% (36/46) . SEMA3B and SEMA3F were differently lost in 10 and 11 cases respectively, both the two genes expression were lost in 13 cases.We secondly used the RT-PCR method to evaluate the expression level of SEMA3B and SEMA3F genes in 46 cases of esophageal cancer tissues and adjacent normal tissues. The result showed that, the SEMA3B and SEMA3F transcripts were identified in all non-cancer tissues but was not found respectively in 50%(23/46) and 47.8%(22/46) carcinoma tissues respectively (pO.OOl) with distinct expression patterns. No significant association of abnormal SEMA3B and SEMA3F mRNA expression with histological type, differentiation grade of tumors or patients age and sex was observed (pX).05).Our trial was the first one which studies the relationship between SEMA3B, SEMA3F and clinicopathological characters of lung and esophageal cancer in Chinese population and the first one establishing correlation between lymph node metastasis and lung cancer and their correlation with esophageal carcinoma. We respectively discovered SEMA3B and SEMA3F transcription significantly inactivating in lung and esophageal cancer, suggesting that SEMA3B and SEMA3F genes could play a role of TSG in both lung and esophageal carcinoma. SEMA3B mRNA inactivation has been found associated with lung cancer lymph node metastasis suggest that SEMA3B gene transcription inactivation correlate with lung cancer prognosis. Simultaneous check up of the two genes can improve the diagno...