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Depletion of keratin 8/18 modulates oncogenic potential by governing multiple signaling pathways
Author(s) -
Tiwari Richa,
Sahu Indrajit,
Soni Bihari Lal,
Sathe Gajanan J,
Thapa Pankaj,
Patel Pavan,
Sinha Shruti,
Vadivel Chella Krishna,
Patel Shweta,
Jamghare Sayli Nitin,
Oak Swapnil,
Thorat Rahul,
Gowda Harsha,
Vaidya Milind M.
Publication year - 2018
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/febs.14401
Subject(s) - carcinogenesis , keratin , biology , signal transduction , microbiology and biotechnology , apoptosis , programmed cell death , keratin 8 , cancer research , cancer , genetics
Keratin 8/18, the predominant keratin pair of simple epithelia, is often aberrantly expressed in various squamous cell carcinomas ( SCC s) including skin SCC . Its aberrant expression is correlated with increased invasiveness and poor prognosis of the same, although the underlying mechanism is still unclear. A previous report from our laboratory has shown K8‐mediated regulation of α6β4 integrin signaling and thereby tumorigenic potential of oral SCC ‐derived cells. Another study on transgenic mouse model has shown that during skin carcinogenesis, K8 favors conversion of papillomas toward malignancy. In order to understand the role of K8 and allied mechanism in skin SCC , K8 was stably knocked down in a skin epidermoid carcinoma‐derived A431 cells. K8 downregulation significantly reduced the tumorigenic potential of these cells. In agreement with our phenotypic data, differential quantitative proteomics followed by IPA analysis showed altered expression of many proteins associated with biological functions including ‘Cancer’, ‘Cellular movement’, ‘Cell death and survival’, and ‘Cellular morphology’. Some of these proteins were TMS 1, MARCKSL 1, Ran BP 1, 14‐3‐3γ, Rho‐ GDI 2, etc. Furthermore, to our surprise, there was a significant reduction in K17 protein stability upon loss of K8, probably due to its caspase‐mediated degradation. This was supported by altered TMS 1‐ NF ‐κB signaling, leading to increased apoptotic sensitivity of A431 cells which in turn affected ‘Cell death and survival’. Moreover, MARCKSL 1‐Paxillin1‐Rac axis was found to be deregulated bestowing a possible mechanism behind altered ‘Cellular movement’ pathway. Altogether our study unravels a much broader regulatory role of K8, governing multiple signaling pathways and consequently regulating oncogenic potential of skin SCC ‐derived cells. Database Proteome Xchange Consortium via PRIDE database (dataset identifier PXD007206).