Mutations in the tumor suppressor p53 are detectable in over 50% of all human malignancies. Mutant p53 protein is incapable of transactivating its downstream target genes that are required for DNA repair and apoptosis. Chronic exposure to UVB induces p53 mutations and is carcinogenic in both murine and human skin. CP-31398, a styrylquinazoline compound, restores the tumor suppressor functions of mutant forms of p53 in tumor cells. However, its effectiveness in vivo remains unclear. Here, we demonstrate that CP-31398 blocked UVB-induced skin carcinogenesis and was associated with increases in p53, p21, and BclXs. CP-31398 downregulated Bcl2, proliferating nuclear cell antigen, and cyclin D1. Activation of caspase-3 and cleavage of poly (ADP-ribose) polymerase also occurred in both tumor and perilesional skin following treatment. CP-31398 induced the expression of p53-dependent target proteins, and this was followed by apoptosis in UVB-irradiated wild-type mice but not in their p53-deficient littermates. Similar effects were observed in human skin carcinoma A431 cells expressing mutant p53. In addition, CP-31398 induced mitochondrial translocation of p53, leading to changes in mitochondrial membrane permeability pore transition (MPT) and consequent cytochrome c release in these cells. Blocking MPT diminished p53 translocation and apoptosis. These studies indicate that reconstituting p53 tumor suppressor functions in vivo by small molecular weight compounds may block the pathogenesis and progression of skin cancer.

:  Resveratrol (trans‐3,4′,5‐trihydroxystilbene) is a naturally occurring polyphenolic phytoalexin found in grapes, and has been shown to inhibit the growth of various types of cancer cells. We investigated the mechanism of the antiproliferative effect of resveratrol in A431‐transformed keratinocytes harbouring mutant p53, and show that it is accompanied by G1 cell cycle arrest, which coincides with a marked inhibition of G1 cell cycle regulatory proteins, including cyclins A and D1 and cyclin‐dependent kinase (CDK)6 and p53‐independent induction of p21WAF1. Cell cycle arrest was also associated with the accumulation of hypophosphorylated Rb and p27KIP1. Resveratrol inhibited mitogen‐activated protein kinase/extracellular signal‐regulated kinase kinase (MEK)1 > extracellular signal‐regulated protein kinase (ERK)1/2 signalling, downregulated c‐Jun, and suppressed activating protein (AP)‐1 DNA‐binding and promoter activity. In addition, the inhibition of MEK1 > ERK1/2 signalling appears to be independent of retinoblastoma protein (pRb) hypophosphorylation in A431 cells, as PD098059 did not suppress pRb phosphorylation. Our results demonstrate that resveratrol affects multiple cellular targets in A431 cells, and that the downregulation of both AP‐1 and pRb contributes to its antiproliferative activity in these cells.

Purpose: Artificial intelligence (AI) technology is poised to revolutionize modern delivery of health care services. We set to evaluate the patient perspective of AI use in diabetic retinal screening. Design: Survey. Methods: Four hundred thirty-eight patients undergoing diabetic retinal screening across New Zealand participated in a survey about their opinion of AI technology in retinal screening. The survey consisted of 13 questions covering topics of awareness, trust, and receptivity toward AI systems. Results: The mean age was 59 years. The majority of participants identified as New Zealand European (50%), followed by Asian (31%), Pacific Islander (10%), and Ma ¯ori (5%). Whilst 73% of participants were aware of AI, only 58% have heard of it being implemented in health care. Overall, 78% of respondents were comfortable with AI use in their care, with 53% saying they would trust an AI-assisted screening program as much as a health professional. Despite having a higher awareness of AI, younger participants had lower trust in AI systems. A higher proportion of Maori and Pacific participants indicated a preference toward human-led screening. The main perceived benefits of AI included faster diagnostic speeds and greater accuracy. Conclusions: There is low awareness of clinical AI applications among our participants. Despite this, most are receptive toward the implementation of AI in diabetic eye screening. Overall, there was a strong preference toward continual involvement of clinicians in the screening process. There are key recommendations to enhance the receptivity of the public toward incorporation of AI into retinal screening programs.