Background: The progressive, multifactorial and multistep dynamic process of
metastasis is the primary cause of
breast cancer (BC) lethality. PROX1 (Prospero-related homeobox 1), as a type of
transcription factor that plays a key role in the formation of lymphatic vessels in animal embryonic development, has been proven to promote or suppress
cancer in a variety of malignant
tumors. However, molecular mechanisms behind PROX1 induced
breast cancer metastases remain elusive. Methods: Changes of PROX1 expression and clinical significance of PROX1 in BC were evaluated by BC tissue, as well as public database. The functional role of PROX1 in
metastases BC was analyzed by transwell assay in vitro, and by lung
metastases model of nude mice in vivo via lentivirus mediated knockdown assays. Mechanism studies were performed by public database screening, western blot and PCR assay, immunoprecipitation, immunofluorescence staining and
luciferase promoter assays. Results: In this study, we found that PROX1 was upregulated in
breast cancer tissues; increased PROX1 expression in
breast cancer was associated with
tumor size,
lymph node metastasis, ER and PR status. Meanwhile, PROX1 can promote
breast cancer invasion and
metastasis in vitro and in vivo. Furthermore, PROX1 can interact with hnRNPK to activate WNT/β-
catenin signaling in
breast cancer cells. Moreover, the interaction of PROX1 and hnRNPK inhibits the ubiquitination of hnRNPK, and subsequently activates WNT pathway to promote the invasion and
metastasis of
breast cancer. Conclusions: In conclusion, our findings indicated PROX1 contributes to
breast cancer EMT and
metastasis and serves as a candidate diagnostic
biomarker and promising therapeutic target for
breast cancer.