Progression of numerous
neoplasms could involve alterations of gap junction channels composed of
connexins (Cxs). Disorders of expression and cellular displacement of Cxs were also found in
endometrial cancer. Gap junctional intercellular communication can be regulated by wide array of agents, for instance,
growth factors, oncogenes, and
steroid hormones. Nevertheless, expressions of Cxs and
progesterone receptor (PR) were not compared in human tissues. This study focused on assessment of expression of
estrogen receptor alpha (
ERalpha) and PRs in relation to the expression of Cx26 and
Cx43 in 88 cases of
endometrial cancer and analysis of these
proteins' expression in comparison with anatomoclinical features. Positive
ERalpha and PR nuclear staining was present in 66 (75%) and 60 (68.2%) of all studied
tumors, respectively. Positive correlation was found between expression of PR and histopathologic type of
tumor (P = 0.026), and negative correlation was drawn with grading (G) (P = 0.002). There were positive reactions to Cx26 and
Cx43 of mainly cytoplasmic location in 60 (68.2%) and 66 (75%) of studied
cancers, respectively.
Progesterone receptor expression correlated negatively with Cx26 in
endometrial cancers (P = 0.016, r = -0.256). Moreover,
ERalpha expression positively correlated with PR expression (P < 0.001, r = 0.678). On the ground of our findings, disorders of Cx expression and altered distribution pattern occur during endometrial
carcinogenesis, and it seems that PR could participate in this fact. Loss of functional gap junctions may occur because of the aberrant expression and localization of Cx26 and
Cx43 in
endometrial cancer.