Extracellular Vesicles Derived from Metastatic Melanoma Cells Transfer α7-nAChR mRNA, Thus Increasing the Surface Expression of the Receptor and Stimulating the Growth of Normal Keratinocytes.

We have previously shown that extracellular vesicles secreted by metastatic melanoma cells stimulate the growth, migration, and stemness of normal keratinocytes. This study showed for the first time that extracellular vesicles secreted by the metastatic melanoma cell lines mel H, mel Kor, and mel P contain, both at the mRNA and protein levels, the α7-type nicotinic acetylcholine receptor (α7-nAChR), which is involved in the regulation of the oncogenic signaling pathways in epithelial cells. Incubation with the vesicles secreted by mel H cells and containing the highest amount of mRNA coding α7-nAChR increased the surface expression of α7-nAChR in normal Het-1A keratinocytes and stimulated their growth. Meanwhile, both of these effects disappeared in the presence of α-bungarotoxin, an α7-nAChR inhibitor. A bioinformatic analysis revealed a correlation between the increased expression of the CHRNA7 gene coding α7-nAChR in patients with metastatic melanoma and a poor survival prognosis. Therefore, extracellular vesicles derived from metastatic melanoma cells can transfer mRNA coding α7-nAChR, thus enhancing the surface expression of this receptor and stimulating the growth of normal keratinocytes. Targeting of α7-nAChR may become a new strategy for controlling the malignant transformation of keratinocytes.

[Melanoma and Human Papillomaviruses: Is There an Outlook for Study?].

Melanoma is one of the most aggressive human malignant tumors. Its incidence and mortality are growing steadily. Ultraviolet irradiation is the main risk factor for melanoma involved in melanomagenesis. The probability of viral etiology of melanoma has been discussed. Human papillomaviruses (HPV) have been mentioned among candidates for its etiologic agents because some HPV types are the powerful carcinogens causing cervical cancer and other cancers. The review analyses the literature data on the association of melanoma with HPV Several groupsfound HPVin skin melanomas as well as in mucosa; viruses of high oncogenic risk were detected in some cases. For some organs the etiological role of high-risk HPV as inducers of invasive carcinomas is confirmed. These organs require special mention: cervix uteri, vulva, vagina, penis, anal region, and oral cavity. However in the majority of the studies in which viral DNA-positive melanomas were found, testing for viral genome expression was not done while this is the fact of primary importance. HPVare found in normal skin and mucous membranes thus creating justifiable threat of tumor specimen contamination with viral DNA in vivo. There are limited data on aggravation of the disease prognosis in papillomavirus-positive melanomas. However, any systematic observation of a sizeable patient group distinguished by that tumor type has not been performed yet. Viral E6 and E7 oncogenes of high-risk papillomaviruses were shown to be able to transform normal human melanocytes in vitro experiments. Thus, we can assume the presence of the association of melanoma with oncogenic HPV. The clinical significance of this problem is indisputable under the conditions of the steady increase in melanoma incidence and mortality rates in Russia and abroad. The problem requires further study.