The Cancer Genome Atlas database was used to analyze the expression of PITX1 with GC prognosis in the Asian population and to assess the potential mechanism of PITX1 in 5-FU and CDDP resistance.
The evidence that PITX1 (pituitary homeobox 1) is a significant tumor suppressor in human cancer remains largely circumstantial, but it clearly warrants further study as little is known about the tumor-inhibitory roles of PITX1 in cutaneous malignant melanoma.
We show that ectopic hPOMC transcription proceeds independently of pituitary-specific Tpit/Pitx1 and demonstrate a novel E2F1-mediated transcriptional mechanism regulating hPOMC We identify an E2F1 cluster binding to the proximal hPOMC promoter region (-42 to +68), with DNA-binding activity determined by the phosphorylation at Ser-337. hPOMC mRNA expression in cancer cells was upregulated (up to 40-fold) by the co-expression of E2F1 and its heterodimer partner DP1.
Using polyclonal PITX1 antibodies, we studied the expression of PITX1 in normal gastric mucosa, atypical hyperplasia, intestinal metaplasia, and cancer tissue samples from 83 gastric cancer patients by immunohistochemistry.
In contrast, PITX1 mRNA expression is decreased in Barrett's esophagus, compared with matching normal squamous esophagus specimens, and is further decreased in Barrett's-associated cancer.