engleski

Increased adenoviral transduction efficacy in human laryngeal carcinoma cells resistant to cisplatin is associated with increased expression of integrin avb3 and coxsackie adenovirus receptor

In the present study we investigated molecular mechanisms of increased adenoviral transduction efficacy in cisplatin-resistant human laryngeal carcinoma cells CA3ST as compared to parental cells HEp2. Using reverse transcription-PCR the genes potentially implicated in adenoviral entry were screened. In cisplatin resistant cells only up-regulation of avb3 integrin was detected, that was additionally confirmed by flow cytometry. Moderately increased expression of CAR was determined in cisplatin resistant CA3ST cells using flow cytometry and measurement of wild type adenovirus Ad5CMVbgal attachment. In order to test the implication of avb3 integrin in transduction efficacy, six HEp2 derived avb3 – expressing clones with graded expression of avb3 were isolated. To certain degree of density, expression of avb3 positively correlated with Ad5CMVbgal transduction efficacy (i.e. increased viral transduction), suggesting a role of avb3 in transduction efficacy. However, HEp2 clones with the highest avb3 expression were negatively correlated with transduction efficacy (i.e. decreased viral transduction). This was shown to be associated with down-regulation of avb5 integrin, also involved in viral transduction, in clones with the highest avb3 expression. The implication of CAR in increased adenoviral transduction efficacy in cisplatin resistant CA3ST cells was further assessed by transduction experiments using adenoviral mutant Ad5FbD639 whose entry is only to a very small extent dependent on the presence of CAR. Indeed, Ad5FbD639 infected 2.5-fold more, in comparison to wild type adenovirus which infected 5 fold more efficiently resistant CA3ST cells than parental HEp2 cells, indicating that increased expression of CAR contributes to increased efficacy of adenoviral transduction. Thus, the data presented provide evidence that both avb3 integrin and CAR are involved in increased adenoviral transduction efficacy in cisplatin resistant CA3ST cells. These findings may have significant implications in human gene therapy using adenoviruses, especially in patients after unsuccessful cisplatin treatment.

cisplatin-resistant cells ; adenovirus type 5 ; transduction efficacy ; transduction ; coxsackie adenovirus receptor ; avb3 integrins

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