Combined Effect Of Cisplatin Research Articles

Hibiscus-cisplatin combination treatment decreases liver toxicity in rats while increasing toxicity in lung cancer cells via oxidative stress- apoptosis pathway

Cisplatin (CIS) is a broad-spectrum anti-carcinogen that causes cytotoxic effects both in normal and cancer cells. The purpose of this study was to test whether Hibiscus sabdariffa (HS) extract can reduce CIS-induced hepatotoxicity in rodents and to assess its anticancer activity in vitro. Treatment with HS extract at daily doses of 500 mg/kg before and after a single dose of CIS (10 mg/kg) reduced hepatotoxicity in Wistar male albino rats. HS extract reduced activity of hepatic damage marker enzymes ( i.e. alanine and aspartate aminotransferases), necrosis, and apoptosis in liver tissues of CIS-treated rats. This hepatic protection was associated with reduced oxidative stress in liver tissues. The antioxidant effects of HS were manifested as a normalization of malondialdehyde levels and glutathione levels which were all raised after CIS-induction. In addition, HS treatment resulted in a decrease of catalase, and superoxide dismutase activity. The combined effects of CIS and HS were also studied in two human lung cancer cell lines (A549 and H460). Treatment with HS (20 μg /mL) enhanced the cytotoxic activity of CIS both in A549 and H460 cell lines. Interestingly, HS increased CIS-induced apoptosis and oxidative stress more clearly in A549 cells indicating that HS extract in combination with CIS could increase the efficacy of CIS in the treatment of cancer.

The effects of cisplatin and jaceosidin on SH-SY5Y neuroblastoma cells: an electron microscopic, molecular and biochemical study

ABSTRACT In this study, our aim was to show both the single and combined effects of cisplatin and jaceosidin in SHSY-5Y neuroblastoma cells. For this purpose, we used MTT cellular viability assay, Enzyme-Linked Immunosorbent Assay (ELISA), Transmission Electron Microscopy (TEM), Immunofluorescence Staining Assay (IFA) and Western blotting (WB) assay. According to MTT findings, IC50 dose was detected as 50 µM cisplatin and 160 µM jaceosidin co-application. Therefore, experimental groups were finally selected as control, cisplatin, 160 µM jaceosidin and Cisplatin +160 µM jaceosidin. Cell viability was decreased in all groups, and the IFA findings confirmed the viability analysis. WB data indicated that matrix metalloproteinase 2 and 9 levels, as indicators of metastasis, decreased. While LPO and CAT levels increased in all treatment groups, it was observed that the activity of SOD decreased. When TEM micrographs were investigated, cellular damages were determined. In the light of these results, it can be said that cisplatin and jaceosidin have a potential to increase the effects of each other synergistically.

Cisplatin Plus Cetuximab Inhibits Cisplatin-Resistant Human Oral Squamous Cell Carcinoma Cell Migration and Proliferation but Does Not Enhance Apoptosis.

Cisplatin is among the most widely used anticancer drugs used in the treatment of several malignancies, including oral cancer. However, cisplatin treatment often promotes chemical resistance, subsequently causing treatment failure. Several studies have shown that epidermal growth factor receptors (EGFRs) play a variety of roles in cancer progression and overcoming cisplatin resistance. Therefore, this study focused on EGFR inhibitors used in novel targeted therapies as a method to overcome this resistance. We herein aimed to determine whether the combined effects of cisplatin and cetuximab could enhance cisplatin sensitivity by inhibiting the epithelial-to-mesenchymal transition (EMT) process in cisplatin-resistant cells. In vitro analyses of three cisplatin-resistant oral squamous cell carcinoma cells, which included cell proliferation assay, combination index calculation, cell cytotoxicity assay, live/dead cell count assay, Western blot assay, propidium iodide staining assay, scratch assay, and qRT-PCR assay were then conducted. Our results showed that a cisplatin/cetuximab combination treatment inhibited cell proliferation, cell motility, and N-cadherin protein expression but induced E-cadherin and claudin-1 protein expression. Although the combination of cisplatin and cetuximab did not induce apoptosis of cisplatin-resistant cells, it may be useful in treating oral cancer patients with cisplatin resistance given that it controls cell motility and EMT-related proteins.

Effects of cisplatin in combination with hyperthermia on biological characteristics of retroperitoneal liposarcoma.

Effects of cisplatin in combination with hyperthermia on biological characteristics of retroperitoneal liposarcoma.

New chalcone-tethered 1,3,5-triazines potentiate the anticancer effect of cisplatin against human lung adenocarcinoma A549 cells by enhancing DNA damage and cell apoptosis

In the pursuit of new compounds for co-treatment to enhance the anticancer efficacy of cisplatin against lung adenocarcinoma, a series of chalcone-tethered 1,3,5-triazines was designed and synthesized. MTT assay was used to evaluate the anticancer activity of the combinations in which two hybrids 10 and 12 were found to significantly inhibit A549 cancer cells viability and their IC50 values were 24.5 and 17 µM, respectively in reference to cisplatin (IC50 = 21.5 µM). The combined effect of cisplatin with each of 10 and 12 was analyzed according to Chou-Talalay method against both A549 and normal human fibroblast cells. Mechanistic studies employing MALDI-TOF MS and fluorescence spectroscopy using Evagreen probe inferred that 10 and 12 induced DNA double strand breaks in contrast to cisplatin which induces DNA interstrand cross-links. Also, DNA damage kinetics study demonstrated the difference in the rate of DNA damage induced by both 10 and 12 alone and in combination with cisplatin. Further Annexin V-FITC/propidium iodide dual staining assay provided evidence that 10 and 12 induced apoptosis via different pattern to cisplatin and their combination with cisplatin promoted more cells to enter late apoptosis and necrosis. Molecular docking of 10 and 12 in the active pocket of DNA dodecamer displayed their binding modes with higher number of stable hydrogen bond donor as well as π-H interactions in reference to the original ligand.

Combined effects of cisplatin and photon or proton irradiation in cultured cells: radiosensitization, patterns of cell death and cell cycle distribution.

The purpose of the current study was to investigate the biological effects of protons and photons in combination with cisplatin in cultured cells and elucidate the mechanisms responsible for their combined effects. To evaluate the sensitizing effects of cisplatin against X-rays and proton beams in HSG, EMT6 and V79 cells, the combination index, a simple measure for quantifying synergism, was estimated from cell survival curves using software capable of performing the Monte Carlo calculation. Cell death and apoptosis were assessed using live cell fluorescence imaging. HeLa and HSG cells expressing the fluorescent ubiquitination-based cell cycle indicator system (Fucci) were irradiated with X-rays and protons with cisplatin. Red and green fluorescence in the G1 and S/G2/M phases, respectively, were evaluated and changes in the cell cycle were assessed. The sensitizing effects of ≥1.5 μM cisplatin were observed for both X-ray and proton irradiation (P < 0.05). In the three cell lines, the average combination index was 0.82–1.00 for X-rays and 0.73–0.89 for protons, indicating stronger effects for protons. In time-lapse imaging, apoptosis markedly increased in the groups receiving ≥1.5 μM cisplatin + protons. The percentage of green S/G2/M phase cells at that time was higher when cisplatin was combined with proton beams than with X-rays (P < 0.05), suggesting more significant G2 arrest. Proton therapy plus ≥1.5 μM cisplatin is considered to be very effective. When combined with cisplatin, proton therapy appeared to induce greater apoptotic cell death and G2 arrest, which may partly account for the difference observed in the combined effects.

Abstract 5270: HSP90 identified by a proteomic approach as druggable target to reverse platinum-resistance in ovarian cancer

Abstract INTRODUCTION: Epithelial ovarian cancer (EOC) represents the gynecologic cancer with the highest mortality rate. Despite a high initial response to platinum (PT)-based chemotherapy, the majority of patients with advanced EOC relapses and develops chemo-resistance that results in treatment failure and poor prognosis. Therefore, understanding the mechanisms underlying PT-resistance and finding strategies to overcome them are urgently needed. METHODS: Three isogenic models of PT-resistance generated by our group from EOC cell lines (TOV-112D, OVSAHO and MDAH) (Sonego M. et al, 2017), were characterized by a proteomic approach taking advantage of two-dimensional differential in gel electrophoresis (2-D DIGE) followed by Mass Spectrometry. Proteomics data were also analyzed by the ingenuity pathway analysis (IPA) software. Synergistic anti-proliferative activity was evaluated by calculating combination indexes (CI) by the Chou-Talalay method and colony formation assay. Apoptosis was measured by flow-cytometry and by western blotting evaluation of caspase-3 and PARP cleavage. In vivo experiments were performed on xenograft model in athymic mice. RESULTS: We identified 23, 24 and 20 differentially expressed proteins in PT-resistant TOV-112D, OVSAHO and MDAH respectively, compared with parental cells. A relevant relationship between all the identified proteins in the three models was highlighted by IPA. Interestingly, eight of the identified proteins, HSP7C, HNRPL, ATPA, EFTU, PHB, HNRPK, LMNA and PHGDH, shared at least within two cell lines, are all included in one main network related with cancer. Notably, the protein chaperone HSP90 emerged as a central hub of this network and its up-regulation was observed in all the PT-resistant cell lines compared with parental counterparts. Further molecular characterization also showed overexpression of HSF1 transcription factor, a relevant HSP90 activator and client protein, in PT-resistant cells. On this bases, we evaluated the effect of cisplatin in combination with two HSP90 inhibitors (17AAG or ganetespib), both in phase II/III clinical development in cancer patients, observing synergistic anti-proliferative activity and reduced colony formation, particularly in PT-resistant cells. These data were confirmed in primary cultures from PT-Resistant ovarian cancer patients. Furthermore we confirmed for the first time in vivo the synergistic antitumor effect of cisplatin and ganetespib combination in TOV112D PT-resistant xenograft model. Increased pro-apoptotic effect and DNA-damage induction by the combination treatment compared to untreated or single agents treated tumors was confirmed both in vitro and in vivo. CONCLUSIONS: Our data suggest an innovative antitumor strategy based on the combination of platinum compounds with HSP90 inhibitors, to re-challenge PT-resistant EOC, that warrants further clinical evaluation. Citation Format: Rita Lombardi, Maura Sonego, Laura Addi, Federica Iannelli, Francesca Capone, Maria Serena Roca, Maria Rita Milone, Alice Costa, Francesca Bruzzese, Biagio Pucci, Gustavo Baldassarre, Alfredo Budillon. HSP90 identified by a proteomic approach as druggable target to reverse platinum-resistance in ovarian cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5270.

Anticancer Effects of Cisplatin in Combination with Paeonia Japonica in YD-10B Cells

Anticancer Effects of Cisplatin in Combination with Paeonia Japonica in YD-10B Cells

Peanut testa extracts enhance anticancer effect of cisplatin against human cholangiocarcinoma cells via modulation of histone deacetylase inhibitory activity

Objective: To investigate the effect of combination treatments of cisplatin and KK4 and ICG15042 peanut testa extracts against cholangiocarcinoma cells in vitro. Methods: The growth inhibition, cell cycle arrest and apoptosis of cholangiocarcinoma cells were determined by 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and flow cytometry analysis, respectively. The levels of proteins involved in apoptosis were assessed using Western blotting assays. The caspase activity was assessed using a colorimetric caspase activity assay. Results: Cisplatin and peanut (KK4 and ICG15042) testa extracts inhibited the growth of cholangiocarcinoma cell lines (KKU- M214 and KKU-100 cells) in a dose- and time-dependent manner. The combination treatments reduced cell viability and induced apoptosis of cholangiocarcinoma cells more efficiently than singledrug treatments. Cancer cell death synergistically mediated by cisplatin and peanut testa extracts was observed in KKU-M214 cells (combination index 1.0). The combination treatments also increased the sub- G1 population and caused KKU-M214 cell cycle arrest at S and G2/ M phases, which were the combined effects of cisplatin (S phase arrest) and peanut testa extracts (G2/M phase arrest). In addition, pERK1/2, Ac-H3, Bcl-2 and proteins related to apoptosis, including Bax and caspases 3, 8, 9, exhibited enhanced expression in KKU- M214 cells. The combination treatments caused down-regulation of p53, whereas the expression of p21 was fairly constant when compared with cisplatin single drug treatment. Conclusions: Peanut testa extracts in combination with cisplatin synergistically reduce cell viability and induce apoptosis through stimulation of caspases 3, 8 and 9 in KKU-M214 cells.

Single and combined effects of cisplatin and doxorubicin on the human and mouse ovary in vitro.

Chemotherapy drugs are administered to patients using combination regimens, and as such the possibility of multiplicative effects between drugs need to be investigated. This study examines the individual and combined effects of the chemotherapy drugs cisplatin and doxorubicin on the human ovary. Although cisplatin and doxorubicin are known to affect female fertility, there is limited information about their direct effects on the human ovary, and none examining the possibility of combined, multiplicative effects of co-exposure to these drugs. Here, human ovarian biopsies were obtained from 14 women at the time of caesarean section, with 38 mouse ovaries also obtained from neonatal C57Bl/6J mice. Tissue was cultured for 6 days prior to analyses, with chemotherapy drugs added to culture medium on the second day of culture only. Treatment groups of a single (5 μg/mL human; 0.5 μg/mL mouse) or double (10 μg/mL human; 1.0 μg/mL mouse) dose of cisplatin, a single (1 μg/mL human; 0.05 μg/mL mouse) or double (2 μg/mL human; 0.1 μg/mL mouse) dose of doxorubicin or a combination of a single dose of both drugs together were compared to controls without drug exposure. Exposure to cisplatin or doxorubicin significantly decreased follicle health in human and mouse, supporting the suitability of the mouse as a model for the human ovary. There was also a significant reduction of mouse follicle number. Human ovarian stromal tissue exhibited increased apoptosis and decreased cell proliferation. Crucially, there was no evidence indicating the occurrence of multiplicative effects between cisplatin and doxorubicin.

Abstract B29: Cisplatin is pro-immunogenic and promotes intrinsic and reactive immune suppression in inflamed and noninflamed ovarian cancer mouse models

Abstract Objective: Front-line therapy in ovarian cancer combines platinum/taxane chemotherapy and surgery. We studied here the role of cisplatin on PDL1 biology in vitro and in vivo in new ovarian tumor models. We also explored the in vivo efficacy of PDL1 blockade in combination with cisplatin. Methods: We analyzed in vitro the time and dose dependent effect of cisplatin on PD-L1 expression on human and murine cell lines with varying susceptibility to the drug. Cisplatin-induced molecular changes were detected via unbiased transcriptomics (RNAseq, Illumina). Mechanisms of tumor cell-intrinsic immune resistance were explored in a series of murine ovarian cancer cell lines with defined genetic traits, including conditional mutations in either Kras (activation), Pten (deletion), or both. The effect of cisplatin in combination with PDL1 blockade was tested in vivo in two syngeneic OC models (2F8 and 2F8cis) that mirror platinum sensitive and moderately resistant tumors, respectively. These models have different inflammation at baseline, with 2F8cis tumors being more inflamed (increased tumor-infiltrating lymphocytes [TILs]-increased necrosis) than 2F8 tumors. Results: Exposure of murine and human ovarian cancer cell lines to IC50 cisplatin triggers increased PD-L1 expression in a time- and dose-dependent manner. The effect is partly mediated by Erk/MAPK pathway, as MEK inhibitor AZD6244 inhibits both the baseline and the cisplatin-induced PD-L1 expression. Gene expression analyses (RNASeq) demonstrate that cisplatin upregulates a number of genes that contribute to tumor immunogenicity and increased tumor-reactive CD8 T cells. The cisplatin-induced proinflammatory effect was also observed in vivo, predominantly in platinum-sensitive 2F8 tumors that show increased T-cell infiltration of both CD8 and FoxP3 Tregs. Tumor PDL1 gene expression is also increased upon cisplatin treatment, as detected by qPCR. Mice with platinum-sensitive (2F8) tumors showed increased survival in response to cisplatin alone and anti-PDL1 alone, compared to the combination, which was not significantly different than control treated hosts. In contrast, cisplatin/anti-PDL1 treatment combination triggered significantly longer survival in mice with moderately resistant (2F8cis) tumors. Conclusion: Overall, these results suggest that exposure to cisplatin has the potential to increase tumor immunogenicity and recognition by CD8 TILs while also triggering immune evasion through PD-L1 upregulation either directly (through tumor cell-intrinsic mechanisms) or indirectly via adaptive immune resistance due to IFNγ secreting TILs. Inflamed and noninflamed respond to anti-PD-L1 alone. although the effect is generally modest. Inflamed tumors with moderate platinum resistance respond to cisplatin/anti-PDL1 combination, and the effect is better than for each agent alone. These results provide the rationale for the design of combination therapies that take into consideration tumor inflammation at baseline and drug-induced immunogenic effects. Citation Format: Shannon Grabosch, Mirna Bulatovic, Feitianzhi Zeng, Tianzhou Ma, Lixin Zhang, Malcolm Ross, Joan Brozick, George Tseng, Esther Elishaev, Robert P. Edwards, Anda Vlad. Cisplatin is pro-immunogenic and promotes intrinsic and reactive immune suppression in inflamed and noninflamed ovarian cancer mouse models. [abstract]. In: Proceedings of the AACR Conference: Addressing Critical Questions in Ovarian Cancer Research and Treatment; Oct 1-4, 2017; Pittsburgh, PA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(15_Suppl):Abstract nr B29.

APIGENIN INCREASES CISPLATIN INHIBITORY EFFECTS ON THE TELOMERASE ACTIVITY OF TRIPLE NEGATIVE BREAST CANCER CELLS

Inhibition of telomerase activity has emerged as a promising strategy to combat cancer cells, especially ones with no specific molecular targets such as triple negative breast cancer (TNBC). Cisplatin, a chemotherapeutic drug, is causing DNA damage while apigenin, a plant-derived antioxidant, induces apoptosis in various cancer cell types. Little is known about their combined ability to inhibit telomerase activity in TNBC cells. In the current study, the effect of cisplatin in combination with apigenin was investigated with regards to telomerase activity and expression of the telomerase catalytic subunit hTERT as well as Heat Shock Protein 90 (Hsp90) and p23 in two types of TNBC (MDA-MB-231; HCC1806) and one non-tumorigenic (MCF10A) epithelial cell line. The results showed that the combined treatment of cisplatin and apigenin significantly down-regulated telomerase activity. The inhibition of telomerase activity was accompanied by a down-regulation of hTERT, Hsp90 and p23 at transcriptional and translational level in both TNBC cells, as compared to control cells. The results of the current study suggest that apigenin and cisplatin synergistically inhibit telomerase activity by downregulating the enzyme’s catalytic subunit. However, the exact roles of Hsp90 and p23 in the regulation of telomerase activity requires further investigation as they seem to be TNBC subtype-specific.

Improved efficacy of cisplatin in combination with a nano-formulation of pentacyclic triterpenediol

Cisplatin is widely used for the treatment of various cancers including cervical, ovarian, lung and head and neck, however, its clinical success is limited owing to the dose-dependent adverse effects, mainly nephrotoxicity and neurotoxicity. In order to address this limitation, the present study was undertaken to investigate growth inhibitory effect of cisplatin in combination with a triterpenediol (3a, 24-dihydroxyurs-12-ene and 3a, 24-dihydroxyolean-12-ene, TPD) on human ovarian cancer cell line. Poly(dl-lactic-co-glycolic) acid nanoparticles loaded with TPD (TPD-PLGA-NPs) were successfully developed by emulsion solvent evaporation method. The TPD-PLGA-NPs were characterized for size distribution and zeta potential which was in order of 152.56±3.01nm and −17.36±0.37mV respectively. The morphological evaluation was carried out by transmission electron microscopy and the formulation was also characterized using Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The drug loading of the optimized formulation was 51.03±1.52μg/mg and the formulation exhibited sustained drug release profile. The in vitro cellular uptake study of coumarin-6 loaded PLGA nanoparticles in OVCAR-5 cells demonstrated a time dependent increase in uptake efficiency. Further, growth inhibitory effect of cisplatin was investigated in combination with TPD-PLGA-NPs. The combination index (CI) was <1, indicating a synergistic interaction. Further, at 75% of cell growth inhibition (ED75) the dose of cisplatin was reduced to 3.8 folds using this combination. The results indicated the potential of cisplatin and TPD-PLGA-NPs combination in order to reduce to dose limiting toxicities of the former.

Effects of Combination Therapy with Cisplatin and Grape Seed Proanthocyanidins on Human Cervical Cancer Cells C33A

To investigated the inhibitory effect of cisplatin in combination with Grape Seed Proanthocyanidins against human cervical cancer cell lines in vitro. Cervical cancer C33A cells were cultured and divided into four groups: cisplatin group, Grape Seed Proanthocyanidins group, cisplatin with Grape Seed Proanthocyanidins group and the blank control group. Morphologic changes of C33A cells were observed under invert microscope after C33A cells were treated 48, and 72 h. The proliferation of C33A cells was determined by CCK8 assay. Apoptosis were evaluated by PE Annexin V staining. Both of these two agents induced apoptosis and inhibited proliferation in C33A cells in a dose-dependent manner. In combination, cisplatin and Grape Seed Proanthocyanidins amplified these regulatory effects compared to each agent alone. The inhibition of proliferation can be observed in cisplatin group and in Grape Seed Proanthocyanidins group with different concentrations, while the notable effect was showed in Grape Seed Proanthocyanidins group. Combination treatment of cisplatin and Grape Seed Proanthocyanidins produces synergistic influence on C33A cells.

Cisplatin in combination with programmed cell death protein5 increases antitumor activity in prostate cancer cells by promoting apoptosis.

Prostate cancer is the most common type of cancer affecting males. The aim of the present study was to investigate the antitumor effect of cisplatin in combination with programmed cell death protein5(Pdcd5) on Du145 prostate cancer cells and to elucidate the underlying mechanisms of action. An MTT cell viability assay was performed in order to determine the proliferation rate of Du145 cells. The results demonstrated that Du145cells treated with cisplatin for 48h had an IC50 value >200µM; however, following transfection of Pdcd5 in combination with treatment with various concentrations of cisplatin, the proliferation rates of Du145 and PC3 prostate cancer cells were significantly decreased in a dose‑dependent manner, with IC50 values of 114.1and 50.6µM, respectively. AnnexinV‑fluorescein isothiocyanate/propidium iodide dual labeling analyses demonstrated a significant increase in the apoptotic rate of Du145 cells following transfection of Pcdc5 in combination with cisplatin treatment. Furthermore, western blot analysis revealed a marked increase in activated caspase‑3 expression in Du145 cells as well as a decreased ratio of Bcl‑2/Bax. In conclusion, the results of the present study demonstrated that Pdcd5 increased the chemosensitivity of prostate cancer cells and decreased the toxicity of cisplatin via activation of the receptor‑associated apoptotic pathway; this may therefore indicate the combined use of cisplatin and Pdcd5 as a novel therapeutic strategy for the treatment of prostate cancer.

Abstract 946: Mitochondrial division inhibitor 1 (mdivi-1) overcomes cisplatin resistance independent of dynamin-related protein 1 (Drp1).

Abstract Platinum based anticancer agents including cisplatin are among the most effective and widely used anticancer drugs. However, the inherent and acquired resistance to these drugs in tumors present significant challenges in cancer treatment and directly lead to treatment failure. We have identified a number of thioquinazolinone derivatives, including the mitochondrial division inhibitor-1 (mdivi-1), that are able to effectively overcome both the inherent and acquired resistance to cisplatin and induce rapid apoptosis in several tumor cell lines. However, the enhanced cellular sensitivity to cisplatin by mdivi-1 was also observed in Drp1 (a mitochondrial fission protein and the supposed target of mdivi-1) knockout MEF cells, indicating Drp1-independent roles of these compounds in overcoming platinum drug resistance. The combination of cisplatin and mdivi-1 induces a robust replication stress response and enhances both intrinsic and extrinsic apoptotic signaling when compared with cisplatin or mdivi-1 treatment alone. Though the combined effect of cisplatin and mdivi-1 is not dependent on mitochondrial fission protein Drp1, mitochondria do play a significant role in the rapid execution of apoptosis triggered by this combination. Highly uncoupled mitochondria, increased generation of reactive oxygen species (ROS) and the release of apoptotic factors were observed only in cells treated with the combination of cisplatin and mdivi-1 and not in cells treated with the compounds individually. Taken together, we have identified novel functions for a set of thioquinazolinone derivatives that are able to overcome platinum drug resistance through enhancing replication stress-mediated apoptotic response. Citation Format: Wei Qian, Vera Roginskaya, Sandra Strychor, Jan Beumer, Lee McDermott, Jingnan Wang, Bennett Van Houten. Mitochondrial division inhibitor 1 (mdivi-1) overcomes cisplatin resistance independent of dynamin-related protein 1 (Drp1). [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 946. doi:10.1158/1538-7445.AM2013-946

Cisplatin and 4-hexylresorcinol synergise to decrease metastasis and increase survival rate in an oral mucosal melanoma xenograft model: a preliminary study

The present study was undertaken to examine the effects of cisplatin plus 4-hexylresorcinol (4-HR) combination therapy on oral mucosal melanoma (OMM) using cultured primary OMM cells in a tumour xenograft model. Cultured primary OMM cells were used for the MTT assay and DNA microarray. OMM cells were implanted into the submandibular glands of nude mice. The mice were then treated with cisplatin only or cisplatin plus 4-HR. Tumour size changes, survival rate and tumour metastasis were compared between the two groups by observation, micro-positron emission tomography (PET) and histological examination. In the MTT assay, the cisplatin plus 4-HR group showed significantly higher inhibition of OMM cell growth compared to the other groups (p<0.05). DNA microarray results showed significant inhibition of matrix metalloproteinase (MMP)-2 gene expression upon 4-HR application. The necropsy and micro-PET results showed that the mice from the cisplatin-only group had more distant metastases than the mice from the cisplatin plus 4-HR combination group (p=0.002). MMP-2 expression was lower in the primary tumours in the cisplatin plus 4-HR combination group than in the cisplatin-only group (p<0.001). Overall survival was longer in mice from the cisplatin plus 4-HR combination group than in the cisplatin-only group (p=0.049). In conclusion, the combined effect of cisplatin and 4-HR resulted in fewer metastases and longer survival than cisplatin-only treatment in the OMM xenograft model.

Селеновмісні сполуки і D-пантетин модулюють дію доксорубіцину та цисплатину на злоякісні клітини із резистентністю до цих препаратів

The aim of this work was to study biological activity of sodium selenite, selenomethionine and D-panthetine towards drug-resistant human leukemia and carcinoma cells, characterized by overexpression of P-glycoprotein and knockout of Bax gene which plays a key role in the induction of cell death. It was found that sodium selenite possessed a pronounced cytotoxic effect on tumor cells already at 10 µM concentration, whereas selenomethionine was much less toxic (active concentration 100 µM) and D-panthetine (vitamin B 5 derivative) showed antitumor activity in 100–1000 µM concentration range depending on the studied cell lines. Studies of anticancer activity of these antioxidants (in physiologically harmless concentrations) in combination with semilethal (LC 50 ) dose of anticancer drugs – cisp­latin and doxorubicin – revealed that all compounds enhanced cytotoxic activity of cisplatin, with most pronounced effect towards drug-resistant cells. Thus, the combined effect of cisplatin and antioxidants significantly enhanced the cytofoxic effect of that drug towards drug-resistant tumor cells. Sodium selenite in low concentrations inhibited cytofoxic action of doxorubicin by 20–25%. That effect was accompanied by a complete inhibition of production of toxic superoxide radicals induced by doxorubicin. We suggest that such ROS-inhibiting effect of sodium selenite might be important in protecting normal cells (e.g., cardiomyocytes) from toxic effects of doxorubicin. Keywords: antioxidants, anticancer drugs, reactive oxygen species, selenomethio­nine, sodium selenite, D-panthetine, tumor cells.

Transfection of PDCD5 Effect on the Biological Behavior of Tumor Cells and Sensitized Gastric Cancer Cells to Cisplatin-Induced Apoptosis

Programmed cell death 5 (PDCD5) expression is reduced in various human tumor cells, and the protein concentration and nuclear translocation of PDCD5 is also observed during tumor cell apoptosis. The purpose of this study was to investigate the differential expression of PDCD5 in six gastric cell lines, and to explore the changes of biological behavior mechanism underlying enhanced apoptosis-inducing effects of cisplatin by PDCD5 over-expression on gastric cancer BGC823 cells. RT-PCR and real-time PCR were used to determine PDCD5 expression. BGC823/PDCD5 cells were assessed the cellular proliferating ability by MTT assay, soft agar cloning experiments and tumorigenicity in nude mice experiments in vivo. The effects of cisplatin in combination with PDCD5 on the proliferation and apoptosis were measured by MTT, Annexin-V-FITC/PI dual labeling and cell cycle analysis, respectively. Immunofluorescence was used to detect co-localization of p53 and PDCD5 protein to explore the mechanism underlying the synergistic therapeutic effect of PDCD5 with cisplatin (5 μg/ml for 24 h). PDCD5 had the highest expression level in the GES1 cell among other cell lines. The growths of BGC823 cells transfected with PDCD5 for six (6th) or 17 (17th) days were both slower than that of BGC823 and BGC823/Neo (P < 0.01). The stable transfection of PDCD5 demonstrated G2/M cell cycle arrest, increased apoptosis and nuclear translocation of PDCD5 and p53 after cisplatin treatment. Stable transfection of the PDCD5 gene can inhibit the growth of the BGC823 cell line and notably improve apoptosis-inducing effects of cisplatin, indicating a novel strategy for better chemotherapeutic effects on gastric cancer.

Transfection of PDCD5 sensitizes colorectal cancer cells to cisplatin-induced apoptosis in vitro and in vivo

This study was purposed to explore the mechanism of augmenting apoptosis-inducing effects of cisplatin on colorectal cancer SW480 cells by stable transfection of Programmed Cell Death 5 (PDCD5) gene, both in vitro and in vivo. The expression level of PDCD5 of SW480 cells stably transfected with PDCD5 (SW480/PDCD5) and pcDNA3.1/Neo(+) empty vector stably transfected cells (SW480/Neo) was examined by real-Time RT-PCR and Western blot. The effects of cisplatin in combination with PDCD5 on the proliferation and apoptosis of colorectal cancer cells were measured by using MTT analysis, Hoechst 33258 analysis and flow cytometry with Annexin-V-FITC/PI dual labeling, respectively. To examine the combination therapeutic effect of PDCD5 and cisplatin, tumor xenograft model was prepared for in vivo study. The results showed that PDCD5 levels of SW480/PDCD5 were higher than SW480 and SW480/Neo, respectively. The PDCD5 enhanced the apoptotic percentage of SW480/PDCD5 cells induced by cisplatin, as compared SW480 and SW480/Neo, respectively. In in vivo study, the transfection of PDCD5 increased the efficacy of cisplatin-induced inhibition of tumor growth in nude mice. It is concluded that stable transfection of PDCD5 gene can notably improve apoptosis-inducing effects of cisplatin on colorectal cancer cells, which is a novel strategy to better chemotherapeutic effects on colorectal cancer.