Background: DACH-Ac-Pt [(1R,2R-diaminocyclohexane)-(trans-diacetato)-(dichloro)-platinum(IV)] is a novel cisplatin (CDDP) analog, and we have evaluated its potential activity in human prostate cancers.
Methods: Cytotoxic, biochemical pharmacologic, cell cycle, and Western blot evaluations were conducted with platinum agents to assess the role of p53 genotype and androgen-dependence status on cellular response.
Results: CDDP and DACH-Ac-Pt were equiactive against mutant p53 and androgen-independent DU-145 or PC-3 tumor cells. In wild-type p53 cells, CDDP was threefold more potent against androgen-dependent LNCaP than isogenic androgen-independent LNCaP-LN3 cells. However, the analog was equipotent in these two wild-type p53 tumor models. The greater potency of DACH-Ac-Pt than CDDP in wild-type p53 cells was not due to increased cellular drug uptake or increased adduct levels, but correlated with a lower tolerance to DNA damage. The analog also activated the p53-p21(WAF1/CIP1) signal transduction pathway more efficiently in LNCaP and LNCaP-LN3 cells, and this induced G(1)-phase cell-cycle arrest. CDDP, in contrast, activated this pathway efficiently in LNCaP cells only. In addition, and compared to CDDP, DACH-Ac-Pt was more effective in inducing Bax and increasing the Bax/Bcl-2 ratios in both the tumor models.
Conclusions: DACH-Ac-Pt is highly effective against wild-type p53 LNCaP and its LN3 variant, and this activity is androgen-independent. The differential induction of p21(WAF1/CIP1) and increase in Bax/Bcl-2 ratios with CDDP and DACH-Ac-Pt in LNCaP-LN3 cells appear to be linked to the relative activity of the two agents against this model.
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http://dx.doi.org/10.1002/pros.20114 | DOI Listing |
Int J Surg Pathol
January 2025
Department of Pathology and Forensic Medicine, Ribeirão Preto Medical School (FMRP/USP), University of São Paulo, Ribeirão Preto, SP, Brazil.
Merkel cell carcinoma (MCC) is an uncommon aggressive neoplasm, usually arising in sun-exposed skin of the head and neck. By immunohistochemistry, KRT20 and MCPyV positivity are found in about 90% and 80% of MCCs, respectively. Noteworthy, viral status in lip/oral cavity MCCs is poorly known.
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Department of Cellular Biochemistry, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
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Center for Precision Medicine Research, Marshfield Clinic Research Institute, Marshfield Clinic Health System, Marshfield, WI, USA.
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January 2025
Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, Texas.
Small cell lung cancer (SCLC) and pulmonary carcinoid tumors are traditionally seen as unrelated, with SCLC linked to smoking and characterized by biallelic loss of RB1 and TP53 and rapid progression. Rekhtman and colleagues upend these assumptions by discovering an "atypical" SCLC that arises in nonsmokers with intact RB1 and TP53 loci, chromothripsis-induced oncogene amplifications on extrachromosomal DNA, and frequent synchronous carcinoid tumors. See related article by Rekhtman et al.
View Article and Find Full Text PDFMol Divers
January 2025
School of Sciences, China Pharmaceutical University, 639 Longmian Avenue, Nanjing, 211198, People's Republic of China.
The p53 protein is regarded as the "Guardian of the Genome," but its mutation is tumor progression and present in more than half of malignant tumors. The pro-metastatic property of mutant p53 makes a strong argument for targeting mutant p53 with new therapeutic strategies. However, mutant p53 was considered as a challenging target for drug discovery due to the lack of small molecular binding pockets.
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