Gemcitabine/Cisplatin Treatment Induces Concomitant SERTAD1, CDKN2B and GADD45A Modulation and Cellular Changes in Bladder Cancer Cells Regardless of the Site of TP53 Mutation

Abstract

Simultaneous use of cisplatin (CIS) and gemcitabine (GEN) for treating bladder cancer has increased because of their complementary effects. However, the molecular mechanisms underlying the activities of these two antineoplastic drugs are not fully known. Here, molecular biology techniques and microscopy were used to investigate transcriptomic and morphological changes in low and high-grade urinary bladder transitional carcinoma cell lines [RT4 - wild type TP53; 5637 - two TP53 mutations, one in codon 72 (Arg-Pro) and other in codon 280 (Arg-Thr) and T24 - in-frame deletion of tyrosine 126 in the TP53 allele] simultaneously treated with CIS/GEN. Gene expression profile was evaluated by PCR arrays; cell morphology by scanning and transmission electron microscopy, and apoptosis was analyzed using fluorescent dye. Results showed concomitantly upregulation of CDKN2B (G1/S transition), GADD45A (DNA repair and apoptosis) and SERTAD1 (regulation of transcription) gene, increased number of nuclear chamfers and apoptotic cells, and reduced number of microfilaments, organelles and in the size of the nucleus in 5637 and T24 cells after simultaneous treatment with CIS/GEN. In conclusion, independently of the TP53 mutation status and tumor grade, CIS/GEN induced gene modulation accompanied by changes in cell morphologies, which confirm the antiproliferative activity of the treatment protocol. These findings help to understand the pathways modulated by these antineoplastic agents and may provide insights for anti-cancer chemotherapy.

Cisplatin Induced the Expression of SEI1 (TRIP-Br1) Oncogene in Human Oral Squamous Cancer Cell Lines

“…The aforementioned results indicate that to a certain extent, cisplatin inhibition in OSCC cell lines is independent of TP53 status. This observation is consistent with previous studies showing that cisplatin inhibits cell cycle progression and/or induces apoptosis in cells in both p53-dependent and p53-independent manners (23,24,(30)(31)(32).…”

“…Previous studies have shown that the intrinsic transactivation activity of p34 SEI1 is able to modulate the E2F-related and p53related transcription, thus up-regulating the expression of cyclin E and p21 in cells, respectively (23,24). Hence, we continued to evaluate the expression of cylcin E and p21 in these OSCC cells upon cisplatin treatment.…”

“…Interestingly, it has been reported that up-regulation of SEI1 in breast cancer cells inhibited hypoxia-induced apoptosis and autophagy, thus providing cancer cells resistance to the hypoxia-induced cell death (22). In addition, it has been demonstrated that cisplatin treatment induced up-regulation of SEI1 in bladder cancer cells regardless of the TP53 gene status (23,24). With regard to all these findings, we postulated that up-regulation of SEI1 might underlie the development of resistance to cisplatin, an apoptosis-induced agent, in OSCC.…”

Bladder Cancer Chemosensitivity Is Affected by Paraoxonase-2 Expression

“…T24 cells downregulating and overexpressing PON2, as well as controls, were seeded in 96-well plates (3 × 10 3 cells/well). The day after seeding, cells were treated with cisplatin and gemcitabine, as previously reported [29,30]. In particular, cells were incubated with cisplatin (20 µmol/L), gemcitabine (6.25 µmol/L), or a combination of both drugs (1.0 µmol/L cisplatin and 1.56 µmol/L gemcitabine) for 24 h. After incubation with drugs, cells were washed with phosphate-buffered saline and complete fresh medium was added.…”

Carfilzomib inhibits the growth of lung adenocarcinoma via upregulation of Gadd45a expression

“…Gadd45a modulates cell cycle regulation, DNA replication/ repair, cell proliferation, apoptosis, and genomic stability via interaction with partner proteins, such as proliferating cell nuclear antigen (PCNA), P21, cyclindependent kinase 1 (CDK1)/cyclin B1 complex, elongation factor-1 α (EF-1α), and mitogen-activated protein kinase kinase kinase 4 (MEKK4) (Takekawa and Saito, 1998;Jin et al, 2000Jin et al, , 2002Tong et al, 2005). Upregulation of Gadd45a is observed after several anti-cancer treatments and is involved in the efficacy of these treatments (da Silva et al, 2018;Li et al, 2018). Therefore, understanding the function of Gadd45a after CFZ treatment will pave the way for unveiling the mechanism that renders CFZ its remarkable effectiveness.…”