Concentrations Of Cisplatin Research Articles

PRDX3 promotes resistance to cisplatin in gastric cancer cells.

This study aims to investigate peroxiredoxin 3 (PRDX3) expression in gastric cancer tissue and its effects on cisplatin resistance in gastric cancer cells and its possible mechanism. PRDX3 expression in human gastric cancer tissue microarrays was detected via immunohistochemistry. The PRDX3 small interfering RNA (siPRDX3 group) and the negative control siNC (siNC group) were transfected into AGS and MKN-74 cell lines, respectively, whereas a blank control group was set up. Each group was treated with different cisplatin concentrations (0, 5, 10, 15, 20, 25, and 30 μg/ml), and the half-inhibitory concentration (IC50) of each group of the two cell lines was calculated using the CCK8 assay. The corresponding IC50 concentration of the siPRDX3 group in the two cell lines was used to treat cells of each group. Flow cytometry was used to detect cell apoptosis, and Western blotting was used to detect the expression levels of cleaved caspase-3 and Bax in each group. PRDX3 was overexpressed in gastric adenocarcinoma tissue compared with adjacent noncancer tissue (P = 0.0053). After cisplatin treatment, the IC50 in the siPRDX3 group of AGS cells (5.91 ± 0.18 μg/ml) and the siPRDX3 group of MKN-74 cells (3.48 ± 0.30 μg/ml) was significantly lower than in the corresponding siNC groups (10.01 ± 0.99 and 6.39 ± 0.70 μg/ml; P = 0.0022 and 0.0027, respectively). AGS cells (38.81% ± 1.69%) and MKN-74 cells (25.03% ± 2.80%) in the siPRDX3 group showed significantly higher apoptosis rates than in the corresponding siNC groups (23.17% ± 1.43% and 16.7% ± 1.39%; P = 0.0003 and 0.0099, respectively). The expression levels of cleaved caspase-3 and Bax were significantly higher in the siPRDX3 group of both cell lines than in the siNC group (P < 0.0001). PRDX3 increases the gastric cancer cell resistance to cisplatin by reducing apoptosis and thus may serve as a target to overcome cisplatin resistance.

The copper transporter CTR1 and cisplatin accumulation at the single-cell level by LA-ICP-TOFMS.

More than a decade ago, studies on cellular cisplatin accumulation via active membrane transport established the role of the high affinity copper uptake protein 1 (CTR1) as a main uptake route besides passive diffusion. In this work, CTR1 expression, cisplatin accumulation and intracellular copper concentration was assessed for single cells revisiting the case of CTR1 in the context of acquired cisplatin resistance. The single-cell workflow designed for in vitro experiments enabled quantitative imaging at resolutions down to 1µm by laser ablation-inductively coupled plasma-time-of-flight mass spectrometry (LA-ICP-TOFMS). Cisplatin-sensitive ovarian carcinoma cells A2780 as compared to the cisplatin-resistant subline A2780cis were investigated. Intracellular cisplatin and copper levels were absolutely quantified for thousands of individual cells, while for CTR1, relative differences of total CTR1 versus plasma membrane-bound CTR1 were determined. A markedly decreased intracellular cisplatin concentration accompanied by reduced copper concentrations was observed for single A2780cis cells, along with a distinctly reduced (total) CTR1 level as compared to the parental cell model. Interestingly, a significantly different proportion of plasma membrane-bound versus total CTR1 in untreated A2780 as compared to A2780cis cells was observed. This proportion changed in both models upon cisplatin exposure. Statistical analysis revealed a significant correlation between total and plasma membrane-bound CTR1 expression and cisplatin accumulation at the single-cell level in both A2780 and A2780cis cells. Thus, our study recapitulates the crosstalk of copper homeostasis and cisplatin uptake, and also indicates a complex interplay between subcellular CTR1 localization and cellular cisplatin accumulation as a driver for acquired resistance development.

Evaluation of the Growth Suppressing and Stemness Inhibiting Effect of Cisplatin and 5 Fluorouracil on Human Epithelial Squamous Cell Carcinoma (HEp-2)

An increasing area of research interest in the field of cancer is a subpopulation of cells that have been implicated in tumor sustainability and cancer relapse - cancer stem cells - owing to the striking similarities between them and normal stem cells. In this study, we investigated the apoptosis inducing and stemness inhibiting potential of cisplatin and 5-fluorouracil on the resistant human epithelial squamous cell carcinoma (HEp-2). HEp2 cells were made resistant to 5-fluorouracil and cisplatin by exposing them to low concentration of 5-fluorouracil and cisplatin for 1 month. The resistant cells were assayed for DNA Fragmentation, apoptosis, and induction of stemness. The IC50 of the drugs on the resistant cells were 11.92µg/mL and 1954µg/mL for cisplatin and 5-fluorouracil respectively. The gene expression profiles show the upregulation of p21as well as stemness genes, SOX2 and OCT4, decreased expression of p53 and BAX in 5 fluorouracil treated cells and an increased expression of BCL2 in cisplatin treated cells. We conclude that pluripotency in these cells is maintained through expression of OCT4 and SOX2 via p21. Hence, the upregulation of p21 may contribute to the mechanism of resistance in Hep2 cells. The findings of this present study lend credence to the possibilities of modulating stemness properties in resistant cells. Future studies should explore the role of more chemotherapy drugs on stemness of a wide range of cancer cells whose increased proliferation is enhanced by cancer stem cells.

Fucoxanthin Inhibits the Proliferation of ABCC2-Over Expressing Cisplatin-Resistance Ovarian Cancer Cells via Inducing Apoptosis

Background: The development of multidrug resistance (MDR) is a major barrier to achieving effective chemotherapy in cancer. Studies have shown that epithelial ovarian cancer initially responds to platinum-based therapy, however, the recurrent type is often resistant to treatment and is associated with high mortality. Fucoxanthin, a natural component found in marine algae, possesses various pharmacologic properties. This study evaluated the cytotoxicity and resistance reversal activity of fucoxanthin on multidrug resistance-associated protein 2 (MRP2)- overexpressing, cisplatin-resistant ovarian cancer cells (A2780RCIS) and their parental cells (A2780). Methods: Cell viability was evaluated in the presence of different concentrations of fucoxanthin or cisplatin or fucoxanthin/cisplatin combination using the MTT assay. Propidium iodide staining and subG1 analysis were used to evaluate fucoxanthin potential for cell cycle modification and apoptosis induction in cancer cell lines. Results: The results showed that fucoxanthin was able to cause similar toxicity in both cell lines via apoptosis induction. Co-treatment of cells with cisplatin (3.125 to 100 µM) and nontoxic concentrations of fucoxanthin (1 and 2.5 µM) did not reverse resistance to cisplatin in A2780RCIS cells. Conclusion: Although fucoxanthin was not able to modify cisplatin resistance in ovarian cancer cells, it was equally effective in inducing apoptosis and death in both A2780 and A2780RCIS cells, indicating it is not an MRP2 substrate.

Molecular mechanism of ion channel protein TMEM16A regulated by natural product of narirutin for lung cancer adjuvant treatment

Cancer chemotherapy drugs are widely criticized for their serious side effects and low cure rate. Therefore, adjuvant therapy as a combination with chemotherapy administration is being accepted by many patients. However, unclear drug targets and mechanisms limit the application of adjuvant treatment. In this study, we confirmed TMEM16A is a key drug target for lung adenocarcinoma, and narirutin is an effective anti-lung adenocarcinoma natural product. Virtual screening and fluorescence experiments confirmed that narirutin inhibits the molecular target TMEM16A, which is specific high-expression in lung adenocarcinoma. Molecular dynamics simulations and electrophysiological experiments revealed the precise molecular mechanism of narirutin regulating TMEM16A. The anticancer effect of narirutin and its synergistic effect on cisplatin were explored by cell proliferation, migration, and apoptosis assays. The signaling pathways regulated by narirutin were analyzed by western blot. Tumor xenograft mice experiments demonstrated the synergistic anticancer effect of narirutin and cisplatin, and the side effects of high concentrations of cisplatin were almost eliminated. Pharmacokinetic experiments showed the biological safety of narirutin is satisfactory in vivo. Based on the significant anticancer effect and high biosafety, naringin has great potential as a functional food in the adjuvant treatment of lung cancer.

Application of Real-Time Cell Analysis Biosensor Technology for Drug Cytotoxicity Studies in Primary Lung Cancer Cells

Biosensing technologies can be used for toxicity studies on cell cultures. The xCELLigence Real-Time Cell Analysis (RTCA) system is a portable label-free detection method with the capability to analyze cellular proliferation, migration, invasion, growth, morphology states, and cytotoxicity of adherent cells in a non-invasive environment. In pharmacological context, most xCELLigence studies were done using cancer cell lines. Hypothetically, implementing the system with primary cell culture can anticipate actions in vivo better than those seen on cell lines. This could potentially provide useful information on how the drug responds to targeted cancer. In this work, we explore the usage of biosensing technology to establish a concept for high-throughput testing of chemotherapeutics agents on primary patient-derived cancer cells. Four self-established primary lung cancer cells (samples A36, A38, A39, and A40) were derived from biopsies of patients, cultured, and tested with cisplatin. The xCELLigence was used to monitor the response of primary lung cancer cells toward different concentrations of cisplatin ranging from 1 to 120 μM. Cisplatin was found to be effective at approximately 20 μM after 48 h of exposure with A38 and A39 showing drug resistance behavior at below 20 μM concentration. The IC50 values were between 22.88 to 76.22 μM. This indicates that the RTCA biosensor technology has good potential in predicting the cell’s response to chemotherapy especially when primary cancer cells are used. This approach can be the fundamental reference in the future to support personalized chemotherapy treatment by providing additional information on metastatic behavior, cytotoxic and drug-resistance effects of the cancer cells.Graphical Abstract

Extrinsic apoptosis and senescence involved in growth kinetics of seminoma to cisplatin.

Seminoma is the most common type of testicular germ cell tumour and is highly sensitive to cisplatin therapy, which has not been fully elucidated. In this study, we comprehensively monitored dynamic changes of TCam-2 cells after cisplatin treatment. At an early stage, we found that both low and high concentrations of cisplatin induced the S-phase arrest in TCam-2 cells. By contrast, the G0G1 arrest was caused by cisplatin in teratoma NTERA-2 cells. Afterwards, high concentrations of cisplatin promoted the extrinsic apoptosis and high expressions of related genes (Fas/FasL-caspase-8/-3) in TCam-2 cells. However, when decreasing the cisplatin, the apoptotic cells were significantly reduced, and accompanied by cells showing senescence-like morphology, positive SA-β-gal staining and up-regulation of senescence-related genes (p53, p21 and p16). Furthermore, the cell cycle analysis revealed that most of the senescent TCam-2 cells were irreversibly arrested in the G2M phase. G2M arrest was also observed in NTERA-2 cells treated with a low concentration of cisplatin, while no senescence-related phenotype was discovered. In addition, we detected the γ-H2AX, a DNA damage marker protein, and reactive oxygen species (ROS) and found both of which were elevated with the increase of cisplatin in TCam-2 cells. In conclusion, the extrinsic apoptosis and senescence are involved in the growth kinetics of TCam-2 cells to cisplatin, which provide some implications for studies on cisplatin and seminoma.

Recapitulating the Pharmacological Interactions of Cetuximab with Sunitinib and Cisplatin in Head and Neck Carcinoma Cells in vitro

Introduction: Cisplatin is extensively used in the treatment of head and neck carcinomas. Cetuximab combination therapy is employed in recurrent and metastatic settings. Sunitinib showed positive results in the treatment of head and neck carcinomas, both as monotherapy or in combination with cetuximab. Nonetheless, the mechanism governing these pharmacological interactions is largely unresolved. This study investigates the impact of cetuximab on the cytotoxicity of cisplatin and sunitinib using cells representative of head and neck carcinoma and the oral epithelium. Methods: The uptake and efflux activities of cells were determined using the prototypical fluorescent substrates 4-[4-[dimethylamino]styryl)-1-methyl pyridinium iodide, Hoechst 33342, and calcein-AM in the presence or absence of specific inhibitors in cells pretreated with cetuximab. The expression of key uptake and efflux drug transporters was analyzed using qPCR and immunofluorescence. Cisplatin and sunitinib cytotoxicities after cetuximab pretreatment were evaluated using the PrestoBlue viability assay. Results: Both tumor and nontumor cells showed significant active drug transport activity. Cetuximab substantially deregulated the expression of key transporters involved in drug resistance in head and neck cancer cells. Transporter expression in the nontumor cell was unaffected. Upon cetuximab pretreatment, the half maximal effective toxic concentration of cisplatin was reduced by 0.75-fold and sunitinib by 0.82-fold in cancer cells. Nontumor cells were not sensitive to cisplatin or sunitinib under the conditions tested. Conclusion: Cetuximab regulates the expression and activity of key membrane drug transporters in head and neck cancer cells, involved in drug resistance. The deregulation of the transport mechanism behind cisplatin and sunitinib uptake reverses drug resistance and enhances the cytotoxicity of both drugs.

ABCG2, CD44 and SOX9 are increased with the acquisition of drug resistance and involved in cancer stem cell activities in head and neck squamous cell carcinoma cells.

Cancer stem cells are a sub-population of cancer cells with self-renewal activity that play key roles in tumor resistance to chemotherapy and radiation. Several cancer stem cell markers have been identified to correlate with clinical prognosis. However, which marker is associated with which cancer stem cell characteristic is unclear. The present study aimed to clarify the relationship between cancer stem cell markers associated with drug resistance acquisition and the characteristics of cancer stem cells. We generated cisplatin-resistant head and neck squamous cell carcinoma cells by culturing cells in increasing concentrations of cisplatin. The cisplatin-resistant head and neck squamous cell carcinoma cells also acquired multidrug resistance and were named resistant HSC-3 (R HSC-3) cells. R HSC-3 showed no differences in cell proliferation or cell cycle distributions compared with parental cells. R HSC-3 cells showed increased drug excretion ability and elevated expression of ATP-binding cassette subfamily G member 2 (ABCG2), a drug excretion pump. R HSC-3 cells also highly expressed CD44, a cancer stem cell marker, and exhibited enhanced cell invasion and spheroid formation abilities. Furthermore, the stem cell-related factor SRY-box transcription factor 9 (SOX9) was identified as increased in R HSC-3 cells by microarray analysis. Knockdown experiments showed that SOX9 and ABCG2 were involved in the drug excretion ability of R HSC3 cells and ABCG2 was involved in the spheroid formation ability of R HSC-3 cells. These results indicate that CD44, SOX9 and ABCG2 expression levels were enhanced in head and neck squamous cell carcinoma cells that acquired multidrug resistance and that these molecules are important for maintaining cancer stem cell characteristics. Overall, regulating CD44, SOX9 and ABCG2 may be a strategy to inhibit cancer stem cells.

Circ-LIMK1 regulates cisplatin resistance in lung adenocarcinoma by targeting miR-512-5p/HMGA1 axis.

This study aimed to unveil the detailed role and new mechanism of circ-LIMK1 in lung adenocarcinoma. Real-time quantitative polymerase chain reaction was performed to analyze the expression of circ-LIMK1, miR-512-5p, and HMGA1. 3-(4,5)-Dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide assay was employed to test the half maximal inhibitory concentration of cisplatin (DDP). Western blot was used to measure the expression of HMGA1, multidrug resistance protein 1, mitochondrial 37S ribosomal protein, and vascular endothelial growth factor A. Colony formation assay, flow cytometry, transwell assay, and tube formation assay were performed to analyze cell functions. Animal models were established to assay the role of circ-LIMK1 in vivo. The expression of circ-LIMK1 was up-regulated in DDP-resistant tumor tissues and cells. Knockdown of circ-LIMK1 reduced DDP resistance, impaired cancer cell growth, migration, invasion, and angiogenesis. circ-LIMK1 targeted miR-512-5p, and HMGA1 was targeted by miR-512-5p. MiR-512-5p absence could restore the repressive effects of circ-LIMK1 knockdown on lung adenocarcinoma cell phenotypes. Overexpression of HMGA1 could restore the inhibitory effects of miR-512-5p enrichment on lung adenocarcinoma cell malignant phenotypes. Knockdown of circ-LIMK1 could reduce growth of DDP-resistant tumors in vivo. Collectively, circ-LIMK1 regulated DDP resistance in lung adenocarcinoma by targeting miR-512-5p/HMGA1 axis.

Investigation of the effect of gossypin on MMP-2 and MMP-9 genes in prostate cancer cells

Purpose: The aim of this study is to explore the effects of gossypin on matrix metalloproteinases -2 (MMP-2) and MMP-9 genes in prostate cancer cells. Materials and Methods: PC3 cells were grown in culture and treated with three different concentrations of gossypin (25-50-100 µg/ml) and cisplatin (50 µM) as a positive control. First, RNA isolation was performed. Then, cDNA synthesis was performed and RT-PCR was used to evaluate mRNA expression levels of MMP-2 and MMP-9 genes.Results: Gossypin decreased MMP-2 and MMP-9 mRNA expression in prostate cancer cells in a concentration-dependent manner. Three concentrations (25-50-100 µg/ml) of gossypin in PC3 cells reduced the mRNA expression of the MMP-2 gene. While the fold change value of MMP-2 gene expression was 0.3482 ± 0.040 in the 100 µg/ml gossypin group, it was 1.007 ± 0.1425 in the control group. In addition, 50 µg/ml and 100 µg/ml concentrations of gossypin decreased the mRNA expression of the MMP-9 gene. The expression level of the MMP-9 gene in prostate cancer cells was 0.4740 ± 0.038 in the 100 µg/ml gossypin administered group, while it was 1.009 ± 0.1687 in the control group. There was a positive correlation between the expressions of the MMP-2 and MMP-9 genes.Conclusion: According to the results obtained, it is seen that gossypin reduces the expression of MMP-2 and MMP-9 genes in prostate cancer cells and the effects of gossypin on other genetic and epigenetic mechanisms in cancer need to be investigated to reveal the anti-cancer.

The Oxidative and Cytotoxic Effects of Resveratrol Compared With Cisplatin in the LNCap Prostate Cancer Cell Line

Introduction: Prostate cancer is one of the most common diseases worldwide, and many efforts are made to treat this disease; however, these efforts seem to be futile. Accordingly, this study tends to compare the cytotoxic and oxidative (as shown by the production of reactive oxygen species (ROS)) effects of resveratrol in comparison with cisplatin in a prostate cancer cell line (LNCap). Methods: After treatment of LNCap cells with the concentrations of 1, 10, 100, 500, and 1000 µg/mL of resveratrol, and 1, 5, 10, and 50 µg/mL of cisplatin, the viability percentage of cells was analyzed using MTT and spectrophotometry. Also, ROS production in this cell line at the IC50 concentrations of cisplatin and resveratrol was analyzed using flow cytometry. Results: The results of the MTT test showed that cisplatin and resveratrol could both reduce cell viability at high concentrations because of increased cytotoxicity. Measurement of ROS production showed that cisplatin and resveratrol increased ROS levels compared to control cells.Conclusion: The results obtained from this study showed that resveratrol, as a plant derivative, had anticancer and antioxidant properties against the LNCap prostate cancer cell line. Because of the side effects of cisplatin, it can be replaced by resveratrol as a good candidate to be used in chemotherapy.

Wilms tumor 1 associated protein promotes epithelial mesenchymal transition of gastric cancer cells by accelerating TGF-β and enhances chemoradiotherapy resistance.

Wilms tumor 1 associated protein (WTAP) is a key RNA n6-methyladenosine (m6A) methylase, which predicts the occurrence of many diseases, such as liver fibrosis formation, coordinating cancer stem cell function, and promoting tumor development. Gastric cancer (GC) is one of the most common malignant tumors worldwide. However, the role of WTAP in GC development and drug resistance remains unclear. Biological methods and data analysis were used to investigate the expression of WTAP in gastric carcinoma tissue. The expression of transforming growth factor-beta (TGF-β) and epithelial mesenchymal transition (EMT) in GC cells were detected by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blot (WB) with WTAP overexpression cell lines and WTAP knockout cell lines. Gradient concentrations of cisplatin (DDP), gradient cyclophosphamide (CTX), or radiation X-rays were added to WTAP overexpression cell lines and WTAP knockdown cell lines to observe the change of cell viability after radiotherapy and chemotherapy treatment. The expression of WTAP in gastric carcinoma tissue significantly increased as determined by bioinformatics analysis, and a high expression of WTAP was closely associated with poor prognosis of gastric cancer patients. Overexpression of WTAP promoted migration and EMT of GC cells and promoted the expression of TGF-β and the stability of mRNA. WTAP knockdown inhibited migration of GC cells and decreased TGF-β expression and stability of mRNA. In addition, WTAP promoted multiple chemotherapy resistance and radiotherapy resistance in GC. WTAP is a potential predictive biomarker for GC. Our findings revealed a novel mechanism by which WTAP regulates chemoradiotherapy resistance, extending the understanding of the m6A machinery in TGF-β induced EMT and metastasis in GC.

Nanoparticle-based Olaparib delivery enhances its effect, and improves drug sensitivity to cisplatin in triple negative breast cancer

PurposeUltrasound-mediated nanobubbles destruction (UTND) technology could enhance drug transport efficiency and increase the local drug concentration. We structured a novel Olaparib-loaded nanobubbles (Ola-NBs). Then investigated its ability to inhibit triple negative breast cancer (TNBC) cell growth in vitro. Additionally, we observed the change of cisplatin sensitivity before and after Olaparib treatment. MethodsThe Ola-NBs were prepared using extrusion and thin-film hydration combination methods. Cell viability was checked by CCK-8 assay, and calculated the 50% inhibition concentration (IC50) of Olaparib and cisplatin. Next, Jc-1 staining was used to observe mitochondrial membrane depolarization, and an apoptosis assay was applied to assess the apoptosis in different groups. Finally, a Western blot assay was used to evaluate the inhibition effect of Olaparib on TNBC at the molecular level. ResultsOla-NBs were prepared successfully. The zeta potential was −0.617 ± 0.197 mV, and the average diameter was 473.52 ± 17.33 nm. The IC50 of Olaparib had not significant difference in TNBC cells. However, the IC95 was higher in cisplatin-resistant MDA-MB-231 cells (MDA-MB-231/CDDP). The cell viability decreased following Olaparib treatment and was more obvious in the Ola-NBs group (P < 0.05). In addition, the IC50 of cisplatin was lower in the post-Olaparib treatment group. Jc-1 results revealed that the mitochondrial membrane decreased more strongly in the Ola-NBs and combination therapy groups. And the results of Jc-1 corroborated the apoptosis assay results. Moreover, Bax protein expression level increased, while Bcl-2 protein expression decreased in the treatment groups. ConclusionOlaparib not only inhibited TNBC cell growth, but it also improved the sensitivity of cisplatin in TNBC cells. And nanobubbles (NBs) might be an effective supporter, because it can enhance the drug efficacy under ultrasound irradiation.

Population pharmacokinetics of cisplatin in small cell lung cancer patients guided with informative priors

Cisplatin-etoposide treatment is recommended as a first line in small cell lung cancer patients (SCLC). However, the prognosis is poor and the dosing is not tailored beyond the body surface area, which is related with indeterminate cisplatin exposure-response relationship. We aimed to evaluate cisplatin pharmacokinetics (PK) and the exposure to unbound cisplatin in SCLC patients using the informative priors, and assess the relationship between the cisplatin exposure and probability of neutropenia. Observational clinical study was performed including 17 cisplatin-treated SCLC patients. External population cisplatin PK models were identified and NONMEM® software and $PRIOR subroutine were used for the model evaluation. The bias and precision of the model-predicted cisplatin concentrations were evaluated. The best models were combined in a final model including several sets of informative priors, which was used to estimate individual cisplatin exposure, analyze the relationship between the exposure and neutropenia and simulate several cisplatin dosing regimens in a virtual patient cohort. The models by Urien with the informative priors best fitted the data. The individual cisplatin exposure ranged between 2430 and 4560μg*h/L. There was a trend of increasing probability of neutropenia and febrile neutropenia with increasing cisplatin exposure. Approximately 50%, 75% and 90% of patients receiving 60mg/m2, 70mg/m2 and 80mg/m2, respectively, achieved the previously identified exposure threshold of 2860μg*h/L. We developed a tool to individualize cisplatin dosing based on the estimated probability of neutropenia. The benefit of more intense dosing regimens in SCLC patients should be further assessed.

Nanosecond electric pulses are equally effective in electrochemotherapy with cisplatin as microsecond pulses.

BackgroundNanosecond electric pulses showed promising results in electrochemotherapy, but the underlying mechanisms of action are still unexplored. The aim of this work was to correlate cellular cisplatin amount with cell survival of cells electroporated with nanosecond or standardly used 8 × 100 μs pulses and to investigate the effects of electric pulses on cisplatin structure.Materials and methodsChinese hamster ovary CHO and mouse melanoma B16F1 cells were exposed to 1 × 200 ns pulse at 12.6 kV/cm or 25 × 400 ns pulses at 3.9 kV/cm, 10 Hz repetition rate or 8 × 100 μs pulses at 1.1 (CHO) or 0.9 (B16F1) kV/cm, 1 Hz repetition rate at three cisplatin concentrations. Cell survival was determined by the clonogenic assay, cellular platinum was measured by inductively coupled plasma mass spectrometry. Effects on the structure of cisplatin were investigated by nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry.ResultsNanosecond pulses equivalent to 8 × 100 μs pulses were established in vitro based on membrane permeabilization and cell survival. Equivalent nanosecond pulses were equally efficient in decreasing the cell survival and accumulating cisplatin intracellularly as 8 × 100 μs pulses after electrochemotherapy. The number of intracellular cisplatin molecules strongly correlates with cell survival for B16F1 cells, but less for CHO cells, implying the possible involvement of other mechanisms in electrochemotherapy. The high-voltage electric pulses did not alter the structure of cisplatin.ConclusionsEquivalent nanosecond pulses are equally effective in electrochemotherapy as standardly used 8 × 100 μs pulses.

STUB1-SMYD2 Axis Regulates Drug Resistance in Glioma cells.

SET and MYND domain-containing protein 2 (SMYD2) is an important epigenetic regulator that methylates histone and non-histone proteins. The study aimed to investigate the oncogenic role of SMYD2 in gliomas and explore its degradation mechanism induced by cisplatin. Tumor tissue microarray of 441 patients with glioma was collected for SMYD2 immunohistochemical staining. Kaplan-Meier survival curves were constructed using the overall survival values. mRNA-sequencing analysis was performed for understanding the downstream mechanisms mediated by SMYD2. The half-inhibitory concentrations (IC50) of temozolomide and cisplatin in AZ505-treated and control cells were calculated. The potential E3 ubiquitin ligase of SMYD2 was predicted in UbiBrowser and confirmed by a knockdown test. The effect of SMYD2 and its E3 ligase on apoptosis and migration of glioma cells was determined via cell-function assays. High SMYD2 expression correlated with a high WHO stage (P = 0.004) and a low survival probability (P = 0.012). The inhibition of SMYD2 suppressed the process of epithelial to mesenchymal transition (EMT) by downregulating the expression of Collagen 1A1 (COL1A1). AZ505 treatment significantly increased the drug sensitivity of glioma cells. SMYD2 expression was markedly reduced by cisplatin treatment via STIP1 Homology And U-Box Containing Protein 1 (STUB1)-mediated degradation. The knockdown of STUB1 could partly reverse the cell function impairment induced by cisplatin. Our findings suggested that SMYD2 could be a potential drug target for the treatment of gliomas, and STUB1-mediated degradation of SMYD2 plays an important role in reversing chemotherapy resistance in patients with gliomas.

Addition of Gallic Acid Overcomes Resistance to Cisplatin in Ovarian Cancer Cell Lines.

Ovarian cancer is one of the leading causes of cancer-related mortality in women, and is often associated with drug resistance. Therefore, finding effective drugs, including naturally derived compounds, is urgently needed. Herein, we aimed to test the anti-cancer potential of gallic acid monohydrate (GA) and its congeners on cisplatin-sensitive (A2780S), and resistant (A2780CP) ovarian cancer and normal ovarian (HOSE6-3) cell lines. Cytotoxicity was assessed by AlamarBlue and CCK08 assays by exposing cells to different concentrations of cisplatin (0-21µg/mL), GA and its congeners (0-100µg/mL), and a combination of GA and cisplatin. Apoptosis was estimated by Hoechst stain and monitoring the relative RNA expression of the apoptotic effector caspase-3 using qRT-PCR. GA decreased cell viability in a concentration-dependent manner in all cell lines, with an IC50 of 19.39µg/mL (A2780S), 35.59 µg/mL (A2780CP), and 49.32µg/mL (HOSE6-3). GA displayed higher cytotoxicity than its congeners. An apoptotic rate estimation of approximately 20% and 30% was obtained in A2780S and A2780CP. While the cytotoxicity observed with cisplatin and GA was comparable, combining the two enhanced the cytotoxicity significantly, especially in the A2780CP cell line (p<0.05). These data suggest that GA may help overcome the resistance. Hence, the cytotoxic effects of GA, especially on chemo-resistant ovarian cancer cells merit further investigation.<br />.

Gossypin'in farklı kanser hücre dizilerinde HSP60 ve HSP70'in gen ekspresyonu üzerindeki etkisi

Purpose: The aim of this study is to evaluate the impact of gossypin on the expression level of heat shock proteins (HSPs) genes in different cancer cells.&#x0D; Materials and Methods: Cells were grown under standard culture conditions. Cancer cells were treated with different concentrations (5-100 µg/ml) of gossypin and cisplatin (50 µM) as positive control. Cell viability and effective dose range (5-100 µg/ml) of gossypin were determined by MTT at 24, 48 and 72 hours. After RNA isolation and cDNA synthesis, HSP60 and HSP70 gene expression levels were analyzed using RT-PCR. For gene expression analysis, the 2-∆∆ct method was used.&#x0D; Results: According to the MTT results, 25-50-100 µg/ml of gossypin doses were found effective on HSP60 and HSP70 gene expression levels in the cancer cell lines. Gossypin affected with dose-dependently the expression of HSP60 and HSP70 in the three cell lines. In the three cell lines, 50 µg/ml and 100 µg/ml of gossypin doses significantly reduced the expression of HSP60 and HSP70 compared to control group.&#x0D; Conclusion: Our results strongly supported the anticarcinogenic effect of gossypin at various doses in different cell lines. However, we believe that further in vivo research and human studies are needed. Our findings suggest that gossypin could be suitable candidate agent for further investigation to develop new strategies for the prevention and/or treatment of different cancer types.

Abstract 3714: The antitumor activity of cannabis sativa and CBD in prostate cancer PC3 cells

Abstract Prostate cancer is the second most frequently occurring carcinoma in males worldwide and one of the leading causes of death in men around the world. Recent studies estimate that over 1.4 million males are diagnosed with prostate cancer on an annual basis, with approximately 375 000 succumbing to the disease annually. With current treatments continuing to show severe side effects, there is a need for new treatments. In this study we looked at the effect of cannabis sativa extract, cannabidiol and cisplatin on prostate cancer cells, PC3. Methods: In addressing the above questions, we employed the MTT assay to measure the antiproliferative effect on PC3 cells following treatment with varying concentrations of Cannabis sativa extract, cisplatin and cannabidiol. xCELLigence was also used to confirm the IC50 activity in which cells were grown in a 16 well plate coated with gold and monitor cell. Caspase 3/7 activity was also measured using 96 well-plate following treatment. Western-blot and qRT-PCR was also used to measure the gene expression of tumor suppressor genes, p53, Bax and Bcl2. Animal studies were employed to measure the growth of PC3-mouse derived cancer to evaluate the effect of compounds in vivo. Results: From the treatment with varying concentrations of Cannabis sativa extract, cannabidiol and cisplatin, we have observed that the three compounds induced antiproliferation of PC3 cancer cell lines through the activation of caspase 3/7 activity. We also observed induction of apoptosis in these cells following silencing of retinoblastoma binding protein 6 (RBBP6), with upregulation of p53 and bax mRNA expression, and a reduction in Bcl2 gene expression. The growth of tumors in the mouse models were reduced following treatment with cisplatin and cannabidiol. Conclusion: We demonstrated that cannabidiol is a viable therapy to treat prostate cancer cells, in combination with silencing of RBBP6. This suggests that cannabidiol rather Cannabis sativa extract may play an important role in reducing cancer progression. Citation Format: Lesetja Raymond Motadi, Nonhlanhla B. Moleya. The antitumor activity of cannabis sativa and CBD in prostate cancer PC3 cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3714.