Nucleus Dj-1/Park7 Acts As A Favorable Prognostic Factor And Involves Mucin Secretion In Invasive Breast Carcinoma In Chinese Population

Background: DJ-1/Park7 is a cancer-and Parkinson's disease-associated protein which has been implicated in various aspects of malignant transformation in human tumors. The aim of this study was to evaluate the relationship between nuclear DJ-1/Park7 expression by immunohistochemistry and clinicopathologic parameters in invasive breast carcinomas in Chinese population. Methods: We assessed 258 cases of invasive breast carcinomas using formalin fixed, paraffin embedded tissues, including invasive ductal carcinoma-not otherwise specified (IDC-NOS) and special types. Results: We found that nuclear DJ-1/Park7 expression in various invasive breast carcinomas were obviously down-regulated than that in normal mammary gland, only except that in mucinous carcinoma. Increased nuclear expression of DJ-1/Park7 was correlated with some clinicopathologic parameters which were indicators of better prognosis, such as better histological grade, lower Ki-67 index, higher ER/PR expression while decreased nuclear location was associated with triple and HER2 negativity. Furthermore, we expanded to mucinous adenocarcinoma and signet-ring cell carcinoma from stomach, colorectum and lung. Interestingly, nuclear expression of DJ-1/Park7 in mucinous carcinoma from different organs had a similar fold higher than that in adjacent normal gland and the nuclear expression level in signet-ring cell carcinoma were intermediate between corresponding normal gland and mucinous carcinoma. Conclusions: We hypothesized that nuclear location of DJ-1/Park7 might indicate favorable prognosis for patients with invasive breast carcinoma and play a potential role in mucin secretion in adenocarcinomas.