In the present study, after observation of upregulation of miR-203 in melanoma patient's serum and also melanospheres as cancer stem cells model, we examined its overexpression on the stemness potential and migration ability of melanoma cells.
Significantly lower miR-145-5p and miR-203-3p expression levels were found in cases with Breslow thickness >1 mm, high Clark level, ulceration and mitotic rate ≥1/mm<sup>2</sup> Conclusion: Our findings point to miR-205-5p as potential biomarker of distant metastases and to miR-145-5p and miR-203-3p as markers of aggressiveness in melanoma.
Here, using human and canine melanoma cells, we elucidated the effects of miR-203 on cyclic adenosine monophosphate response element binding protein (CREB)/microphthalmia-associated transcription factor (MITF)/RAB27a pathway, which is known to be important for the development and progression of human melanoma.
Multivariate analysis indicated that miR-203 could be an independent prognostic marker (P=0.003, HR=2.851, 95% CI=1.439-5.650) in melanoma This study for the first time provided evidence that miR-203 could be an independent potential prognostic marker for patients with melanoma, and might even become a new therapeutic target for the treatment of melanoma.
In addition, this study suggests that agents that can demethylate MIR203 could be a common promising therapeutic agent for the treatment of human and canine melanomas.
Taken together, our results demonstrated that miR-203 regulated melanoma invasive and proliferative abilities in part by targeting BMI1, providing new insights into potential mechanisms of melanoma metastasis.
In conclusion, our data indicated that anti-oncogenic miR-203 had a pivotal role in melanoma through reducing melanosome transport and promoting melanogenesis by targeting kif5b and through negative regulation of the CREB1/MITF/Rab27a pathway.
Our data suggest that miR-203 is a new prognostic factor in canine oral MMs and that miR-205 functions as a tumour suppressor by targeting erbb3 in both canine and human MM cells.