The Functional Study Of The Genes Underlying Tumorigenesis In Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) is the most prevalent pathological type of esophageal cancer in China. Lymphatic metastasis commonly occurs in ESCC patients, and thus, these patients have a poor prognosis; the precise etiology and pathogenesis of esophageal cancer are unclear, and there is a lack of effective methods for early diagnosis. However, interventions that treat precancerous lesions could reverse the evolution of esophageal cancer. EDHB is also known as protocatechuic acid ethyl ester, which is present in a variety of plant species, mainly in the leaves and roots. EDHB is a substrate analog of prolyl hydroxylase and inhibits collagen secretion from breast cancer cells, thus preventing tumor metastasis. Previous studies have shown that EDHB can effectively induce esophageal cancer cell autophagy and apoptosis, and the AKR1C family represents one set of highly expressed genes after EDHB treatment. The aldo-keto reductase (AKR) superfamily of enzymes is critical for the detoxification of drugs and toxins in the human body; these enzymes are involved not only in the development of drug resistance in cancer cells but also in the metabolism of polycyclic aromatic hydrocarbons. To explore the cytotoxic effects of EDHB, esophageal cancer cells with higher (KYSE180) or lower (KYSE510) AKR1C expression levels were evaluated in this study. The proliferation of KYSE180 cells was inhibited more effectively than that of KYSE510 cells by EDHB treatment. Furthermore, the effective subunits of the AKR superfamily, AKR1C1/C2, were quantitatively identified using multiple reaction monitoring (MRM) assays. The sensitivity of esophageal cancer cells to EDHB was significantly attenuated by the siRNA knockdown of AKR1C1/C2. We also demonstrated that AKR1C1/C2 increased the metabolism of ethy1-3,4-dihydroxybenzoate (EDHB) in esophageal squamous cell carcinoma (ESCC) cells. Moreover, the expression of autophagy inducers (Beclin, LC3II and BNIP3) and NDRG1 was significantly elevated in KYSE180 cells, but not in KYSE510 cells, after EDHB treatment. When autophagy was inhibited by 3-methyladenine, KYSE180 cells exhibited an increased sensitivity to EDHB. These results indicated that ESCC patients with high AKR1C1/C2 expression may be more sensitive to EDHB, and AKR1C1/C2 may facilitate EDHB-induced autophagy and apoptosis, thus providing potential guidance for the chemoprevention of ESCC, thus providing potential guidance for the chemoprevention of ESCC.Epithelial-mesenchymal transition (EMT) is one of the most important steps in the migration and resistance of tumor cells. Purine-rich element binding protein alpha (PURa) is a key player in the regulation of the cell cycle and oncogenic transformation. PURa binds to both DNA and RNA directly or indirectly and functions in the initiation of DNA replication and the control of transcription, mRNA transport and translation. Previous study show that PURa can induce EMT. But the molecular mechanism induced by PURa in esophageal squamous cell carcinoma is unknow. In order to confirm that PURa can induce EMT, different ESCC cell lines overexpressiong PURa can detect the high expression of snail and N-cadherin, and low expression of E-cadherin. After knocking-down PURa, we can dectect the low expression of snail and N-cadherin. Transcription level was detected by RNA-seq in KYSE 510 cell with and without overexperssion of PURa. The RNA-seq showed 3475 difference genes that are related with WNT signal pathway and LEF1 and SNAI was overexpression in KYSE 510-PURa cell. So our data suggest that regulation of PURa expression in ESCC cells may serve as a activation factor of WNT signal pathway which induce the high expression of SNAI and downstream genes inducing esophageal epithelial-mesenchymal transitions. The regulation of PURa expression in ESCC cells may serve as a key factor in inducing esophageal EMT and provide an target of therapy.