title: ROCK2/rasHaco-operation induces malignant conversion via p53 loss, elevated NF-κB and tenascin C-associated rigidity, but p21 inhibits ROCK2/NF-κB-mediated progression.
abstract: To study ROCK2 activation in carcinogenesis, mice expressing 4-hydroxytamoxifen (4HT)-activated ROCK2 (K14.ROCKer) were crossed with mice expressing epidermal-activated rasHa(HK1.ras1205). At 8 weeks, 4HT-treated K14.ROCKer/HK1.ras1205cohorts exhibited papillomas similar to HK1.ras1205controls; however, K14.ROCKer/HK1.ras1205histotypes comprised a mixed papilloma/well-differentiated squamous cell carcinoma (wdSCC), exhibiting p53 loss, increased proliferation and novel NF-κB expression. By 12 weeks, K14.ROCKer/HK1.ras1205wdSCCs exhibited increased NF-κB and novel tenascin C, indicative of elevated rigidity; yet despite continued ROCK2 activities/p-Mypt1 inactivation, progression to SCC required loss of compensatory p21 expression. K14.ROCKer/HK1.ras1205papillomatogenesis also required a wound promotion stimulus, confirmed by breeding K14.ROCKerinto promotion-insensitive HK1.ras1276mice, suggesting a permissive K14.ROCKer/HK1.ras1205papilloma context (wound-promoted/NF-κB+/p53-/p21+) preceded K14.ROCKer-mediated (p-Mypt1/tenascin C/rigidity) malignant conversion. Malignancy depended on ROCKer/p-Mypt1 expression, as cessation of 4HT treatment induced disorganized tissue architecture and p21-associated differentiation in wdSCCs; yet tenascin C retention in connective tissue extracellular matrix suggests the rigidity laid down for conversion persists. Novel papilloma outgrowths appeared expressing intense, basal layer p21 that confined endogenous ROCK2/p-Mypt1/NF-κB to supra-basal layers, and was paralleled by restored basal layer p53. In later SCCs, 4HT cessation became irrelevant as endogenous ROCK2 expression increased, driving progression via p21 loss, elevated NF-κB expression and tenascin C-associated rigidity, with p-Mypt1 inactivation/actinomyosin-mediated contractility to facilitate invasion. However, p21-associated inhibition of early-stage malignant progression and the intense expression in papilloma outgrowths, identifies a novel, significant antagonism between p21 and rasHa/ROCK2/NF-κB signalling in skin carcinogenesis. Collectively, these data show that ROCK2 activation induces malignancy in rasHa-initiated/promoted papillomas in the context of p53 loss and novel NF-κB expression, whereas increased tissue rigidity and cell motility/contractility help mediate tumour progression.
authors.affiliation: Section of Dermatology and Molecular Carcinogenesis, School of Medicine, Dentistry and Nursing, College of Medical, Veterinary and Life Sciences, Glasgow University, Glasgow, UK.|Biomedical Science Programme, School of Diagnostic and Applied Health Sciences, Faculty of Allied Health Sciences, University of Kebangsaan, National University of Malaysia, Kuala Lumpur, Malaysia.
authors.forename: S F
authors.initials: SF
authors.lastname: Masre
authors.affiliation: Molecular Cell Biology Laboratory, Cancer Research UK, Beatson Institute for Cancer Research, Garscube Estate, Glasgow, UK.|Institute of Cancer Sciences, University of Glasgow, Glasgow G12 8QQ, UK.
authors.forename: N
authors.identifier: 0000-0002-2342-6843
authors.initials: N
authors.lastname: Rath
authors.affiliation: Molecular Cell Biology Laboratory, Cancer Research UK, Beatson Institute for Cancer Research, Garscube Estate, Glasgow, UK.|Institute of Cancer Sciences, University of Glasgow, Glasgow G12 8QQ, UK.
authors.forename: M F
authors.initials: MF
authors.lastname: Olson
authors.affiliation: Section of Dermatology and Molecular Carcinogenesis, School of Medicine, Dentistry and Nursing, College of Medical, Veterinary and Life Sciences, Glasgow University, Glasgow, UK.
authors.forename: D A
authors.initials: DA
authors.lastname: Greenhalgh
mesh_terms: D000818:Animals; D063646:Carcinogenesis / Q000235:genetics; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D002454:Cell Differentiation / Q000235:genetics; D002471:Cell Transformation, Neoplastic / Q000235:genetics; D003433:Crosses, Genetic; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D015603:Keratinocytes / Q000473:pathology / Q000821:virology; D051379:Mice; D016328:NF-kappa B / Q000235:genetics; D010212:Papilloma / Q000235:genetics / Q000473:pathology; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics*; D012878:Skin Neoplasms / Q000235:genetics* / Q000473:pathology; D013629:Tamoxifen / Q000008:administration & dosage / Q000031:analogs & derivatives; D016159:Tumor Suppressor Protein p53 / Q000235:genetics*; D054462:p21-Activated Kinases / Q000235:genetics*; D054460:rho-Associated Kinases / Q000235:genetics*
chemical_list: D016328:NF-kappa B; D016159:Tumor Suppressor Protein p53; D013629:Tamoxifen; C016601:afimoxifene; C515905:Pak1 protein, mouse; C515855:Rock2 protein, mouse; D054462:p21-Activated Kinases; D054460:rho-Associated Kinases; C495971:Hras protein, mouse; D016283:Proto-Oncogene Proteins p21(ras)