Value of T cell receptor gamma alternate reading frame protein and keratin 5 in endometrial carcinoma

Tumors with different gene expression develop and progress in different ways. To deepen our understanding of the progression in endometrial cancer, and provide a useful tool for accurate diagnosis and prognosis assessment, we identified the new molecular prognostic markers in endometrial carcinoma and analyzed the relationship of them with clinical and pathological features of endometrial carcinoma.

Ninety-four cases of endometrial endometrioid adenocarcinoma with complete data from the Peking University People's Hospital from 2000 to 2008 and 40 cases of normal endometrium were enrolled. Among these, 30 endometrial endometrioid adenocarcinoma samples of different International Federation of Gynecology and Obstetrics (FIGO) stage were selected for further Agilent genome-wide microarray analysis. Significance analysis of microarrays (SAM) was used to identify genes that are significantly associated with tumor progress. Immunohistochemistry was utilized to identify the genes of interest in endometrial carcinoma and normal endometrium. The relationship between the genes and the age, clinical stage, histological grade, myometrium invaded depth, lymph node metastasis status, and the expression of ER, PR, P53, and PTEN were analyzed by χ(2) test.

Analysis between FIGO 1988 stage I and stage III identified a 362-gene "progress signature"; 171 down-regulated and 191 up-regulated genes. Among the alterative genes, TARP (T cell receptor gamma alternate reading frame protein) and KRT5 (keratin 5) decreased 3.57 fold and 5.8 fold in FIGO stage III patients. The expression of TARP in endometrial carcinoma increased compared to normal endometrium, while that of KRT5 decreased (P < 0.05). The expression of TARP and KRT5 decreased when stage, histological grading, myometrium invaded depth increased (P < 0.05). In the cases with lymph node metastasis, the expression of TARP decreased, while the expression of KRT5 did not differ (both P < 0.05) both. The expression of P53 had a negative relationship with the expression of KRT5 (P < 0.05), but not with the expression of TARP (P > 0.05). There was no correlation between the expression of TARP and KRT5 and the expression of ER, PR, PTEN (all P > 0.05). There was no significant difference in TARP and KRT5 expression in patients aged 50 or younger and patients older than 50 (P > 0.05).

The expression of TARP and KRT5 was correlated with the progress of endometrial cancer and their role needs further study.