Objective: To determine PRA and PRB expressions at mRNA and protein levels in endometrial carcinomas, and to correlate the PRA and PRB expressions in tumours with clinical features including grading, surgical stage, degree of myometrial invasion, and lymph node status.
Methods: Sixty-six endometrial carcinomas were investigated with Western blot assays and reverse-transcription polymerase chain reaction. The corresponding clinical information was collected. Spearman's rank correlation was used to test for association between expressions of total PR and PR isoforms in endometrial carcinomas and clinical features.
Results: At protein level, expressions of PRA and PRB were significantly inversely related to grade(r=-0.343, r=- 0.310, P<0.05), and only PRA was inversely related to surgical stage(r=-0.294, P<0.05). Lymph node metastasis was associated with reduced PRA: PRB ratio(r=-0.376, P=0.044), PRA:PRB ratio was lower in the cases with lymph node metastasis compared with that without lymph node metastasis(P=0.047). No correlation was found between protein levels of isoforms of progesterone receptor and degree of myometrial invasion. PR and PRB mRNA expressions were not related to any of the clinical features discussed above.
Conclusion: PRA and PRB protein levels were correlated with grade, but were not correlated with degree of myometrial invasion. Only PRA protein level was related to surgical stage. Decreased ratio of PRA: PRB was related to lymph node metastasis. PR and PRB mRNA levels had no relationship with any of the clinical features discussed above.