CDDP Exposure Research Articles

Cisplatin caused highly delayed cytotoxicity in the immortalized cells derived from S3 segment of mouse kidney proximal tubules

Anti-cancer drug cisplatin (CDDP) causes severe acute kidney injury (AKI). CDDP-induced AKI does not occur immediately after administration, but rather 6 to 10 days after administration. However, the mechanism underling the delayed renal injury by CDDP is not well understood. In a previous investigation using immortalized cells derived from the S1, S2, and S3 segments of the proximal tubules, we found that S3 cells were more sensitive to CDDP than S1 and S2 cells. In this study, we examined whether S1, S2, and S3 cells would be useful in elucidating the mechanism of CDDP-induced delayed renal injury and whether the high sensitivity of S3 cells contributes to CDDP-induced delayed renal injury. Measurement of platinum (Pt) content by ICP-MS showed that Pt accumulation peaked at 15 min after CDDP exposure in each cell type. Even when the medium was replaced with CDDP-free medium after the 15-min CDDP exposure and the cells were further incubated, delayed cytotoxicity was still observed. The S3 cells exhibited greater sensitivity to CCDP than the S1 and S2 cells at all time points after the medium change. To investigate the mechanism of the CDDP-induced delayed cytotoxicity, we examined the cell cycle distribution of cells after CDDP exposure. The results showed that CDDP-induced perturbation of cell cycle was greater in S3 than in S1 and S2 cells. These results suggest that perturbation of the cell cycle in S3 cells due to enhanced CDDP–DNA adduct formation contributes to the high susceptibility of S3 cells to CDDP-induced delayed cytotoxicity.

Ganoboninketal C from Ganoderma boninense improves the efficacy of CDDP-based chemotherapy through inhibiting translesion DNA synthesis

Translesion DNA synthesis (TLS) can bypass DNA lesions caused by chemotherapeutic drugs, which usually result in drug resistance. Given its key role in mutagenesis and cell survival after DNA damage, inhibition of the TLS pathway has emerged as a potential target for improving the efficacy of DNA-damaging agents such as cisplatin (CDDP), a widely used anticancer agent. Unfortunately, few suitable natural TLS inhibitors have been reported. Here, we found that a triterpenoid compound Ganoboninketal C (26-3) from Ganoderma boninense, a traditional Chinese medicine, can impair CDDP-induced TLS polymerase eta (Polη) focus formation, PCNA monoubiquitination as well as mutagenesis. Moreover, 26-3 can significantly sensitize tumor cells to CDDP killing and reduce the proportion of cancer stem cells in AGS and promote apoptosis after CDDP exposure. Interestingly, 26-3 can also sensitize tumor cells to Gefitinib therapy. Mechanistically, through RNA-seq analysis, we found that 26-3 could abrogate the CDDP-induced upregulation of Polη and PIDD (p53-induced protein with a death domain), 2 known factors promoting TLS pathway. Furthermore, we found that activating transcription factor 3 is a potential novel TLS modulator. Taken together, we have identified a natural TLS inhibitor 26-3, which can be potentially used as an adjuvant to improve clinical efficacy.

Piracetam mitigates nephrotoxicity induced by cisplatin via the AMPK-mediated PI3K/Akt and MAPK/JNK/ERK signaling pathways

AimsCisplatin (CDDP) is commonly employed as an antineoplastic agent, but its use is significantly limited by the occurrence of dose-dependent nephrotoxicity, the detailed mechanisms of which remain unclear. This research is aimed to explore the molecular mechanisms of Piracetam (PIR)’s protective effects on nephrotoxicity resulting from CDDP exposure and to elucidate the mechanisms responsible for these effects. Main methodsPIR was given in dosages of 100 and 300 mg/kg body weight for a duration of 15 days; concurrently, on the last day, a single 10 mg/kg dose of CDDP was delivered via intraperitoneal injection. Forty-eight hours post-CDDP injection, the animals were sacrificed to assess nephrotoxicity. Blood samples and renal tissues were taken for biochemical and histopathological investigations. Serum creatinine and blood urea nitrogen (BUN) were measured. AMP-activated protein kinase (AMPK), caspase-9 and nuclear factor kappa b p65 (NF-κB p65) were assessed by immunohistochemistry method. Enzyme-linked immunosorbent assay (ELISA) analysis was employed to determine cytochrome c (Cyt. c), Bcl-2-associated X-protein (BAX), caspase-3, nuclear factor erythroid 2–related factor 2 (Nrf2), Heme oxygenase-1 (HO-1), superoxide dismutase (SOD), tumor necrosis factor alpha (TNF-α), myeloperoxidase (MPO), and interleukin-1β (IL-1β) levels in renal tissue homogenates. The mRNA levels of tumor protein P53 (TP53), phosphatidylinositol-3 kinase (PI3K), protein kinase B (Akt), p38 mitogen-activated protein kinase (p38 MAPK), extracellular signal-regulated kinases (ERK), and c-Jun N-terminal kinases (JNK) were tested by quantitative real-time polymerase chain reaction (qRT-PCR). Additionally, histopathological evaluations of the renal tissues and the binding affinity of PIR to AMPK by molecular docking were also performed. Key findingsPre-treatment with PIR enhanced renal function markers such as urea and creatinine, mitigated histological damage, and diminished inflammatory cell presence in renal tubules. PIR demonstrated antioxidant effects by reestablishing the equilibrium between pro-oxidants and antioxidants such as MPO, HO-1, Nrf2, as well as SOD. Furthermore, PIR inhibited the inflammatory pathways through the MAPK/NF-κB pathway. Additionally, PIR counteracted the CDDP-induced decline in PI3K/Akt activity and hindered caspase-dependent apoptotic processes. SignificanceIn summary, PIR appears to be an effective therapeutic strategy for reducing CDDP-induced nephrotoxicity, attributed to its antioxidant, anti-inflammatory, and antiapoptotic mechanisms. Consequently, PIR may serve as a complementary treatment alongside CDDP to alleviate nephrotoxicity associated with CDDP.

Unravelling biochemical responses in the species Mytilus galloprovincialis exposed to the antineoplastics ifosfamide and cisplatin under different temperature scenarios

This study investigates the chronic impact of two of the most widely consumed antineoplastic drugs, Ifosfamide (IF) and Cisplatin (CDDP), on the bivalve species Mytilus galloprovincialis under current (17 °C) and predicted warming conditions (21 °C). Accompanying the expected increase in worldwide cancer incidence, antineoplastics detection in the aquatic environment is also expected to rise. Mussels were exposed to varying concentrations of IF (10, 100, 500 ng/L) and CDDP (10, 100, 1000 ng/L) for 28 days. Biochemical analyses focused on metabolic, antioxidant and biotransformation capacities, cellular damage, and neurotoxicity. Results showed temperature-dependent variations in biochemical responses. Metabolic capacity remained stable in mussels exposed to IF, while CDDP exposure increased it at 1000 ng/L for both temperatures. Antioxidant enzyme activities were unaffected by IF, but CDDP activated them, particularly at 21 °C. Biotransformation capacity was unchanged by IF but enhanced by CDDP. Nevertheless, cellular damage occurred at CDDP concentrations above 100 ng/L, regardless of temperature. Integrated biomarker responses highlighted CDDP's greater impact, emphasizing the critical role of temperature in shaping organismal responses and underscoring the complexity of environmental stressor interactions.

Ferroptosis is involved in cisplatin sensitivity of the S3 segment of immortalized proximal tubule cells

Cisplatin (CDDP) is administered as an anticancer drug across a broad spectrum of cancer treatments, but it causes severe renal damage. Several studies have attempted to elucidate the cause of CDDP-induced renal injury, but the detailed mechanism remains unclear. We previously found that S3 cells are more sensitive to CDDP than S1 and S2 cells by using immortalized cells derived from S1, S2, and S3 segments of proximal tubules. In this study, we investigated the potential contribution of reactive oxygen species (ROS) to the sensitivity of S3 cells to CDDP. The results showed that S3 cells have high sensitivity to CDDP, paraquat (PQ) and three ROS substances. To examine the mechanisms underlying the sensitivity to ROS in S3 cells, we compared the cellular responses of CDDP- and PQ-exposed S3 cells. The results indicated that the levels of intracellular ROS and lipid peroxides were increased in S3 cells after CDDP and PQ exposure. The intracellular levels of antioxidant proteins such as thioredoxin, thioredoxin reductase 1 and glutathione peroxidase 4 were also increased by exposure to PQ, but these proteins were decreased by CDDP exposure in S3 cells. Furthermore, the levels of intracellular free Fe2+ were increased by CDDP exposure only in S3 cells but not S1 or S2 cells, and cytotoxicity by exposure to CDDP in S3 cells was suppressed by ferroptosis inhibitors. These results suggested that the induction of ferroptosis due to the ROS production through attenuation of the antioxidant system and elevated free Fe2+ is partly responsible for the sensitivity of S3 cells to CDDP.

Modulation of Heat Shock Protein Expression in Alveolar Adenocarcinoma Cells through Gold Nanoparticles and Cisplatin Treatment.

Heat-shock proteins (HSPs) are stress-responsive molecules belonging to the family of evolutionary molecular chaperones known to be crucial in many cancer types, including human alveolar adenocarcinoma cells (A549). These proteins are highly overexpressed in cancers to support their ability to accommodate imbalances in cell signalling, DNA alterations, proteins, and energy metabolism associated with oncogenesis. The current study evaluated the effects of gold nanoparticles (AuNPs) combined with cisplatin (CDDP) on molecular chaperone HSPs in A549 cells. It was found that AuNPs:CDDP decreased the percentage of cell viability (38.5%) measured using the modified lactated dehydrogenase (mLDH) and 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assays. AuNPs:CDDP exposure caused a significant (p < 0.05) increase in reactive oxygen species (ROS) generation by 1.81-fold, apoptosis induction, and a decrease in the mitochondrial membrane potential (MMP) compared to AuNPs or CDDP alone. Similarly, exposure to the AuNPs:CDDP combination had pronounced cytotoxic effects on the expression of HSPs and PI3K/AKT/mTOR, as well as apoptosis-related proteins. The results demonstrate that the combination of AuNPs with CDDP might enhance the anticancer efficacy of CDDP.

Evaluation of neurotoxicity of anticancer drugs using nematode Caenorhabditis elegans as a model organism.

It is well established that platinum-based drugs, including oxaliplatin (L-OHP) and cisplatin (CDDP), as well as microtubule inhibitors paclitaxel (PTX) and vincristine (VCR), are associated with chemotherapy-induced peripheral neuropathy (CIPN). In this study, we examined and compared the characteristics of neuropathies induced by L-OHP, CDDP, PTX, and VCR to evaluate whether Caenorhabditis elegans (C. elegans) could serve as a model organism for human CIPN. Worms were cultured on nematode growth medium plates, and L1 larvae synchronized by gel filtration were employed. We then performed bioassays and examined motility. In the motility test, exposure was performed for 2, 24, and 48 hr, and time-dependent effects were measured for each exposure time and 24 hr after terminating exposure. Herein, we observed that L-OHP and CDDP exerted concentration-dependent effects above a certain concentration, and PTX and VCR exerted concentration-dependent negative effects in the bioassay. Motility recovered in L-OHP-, PTX-, and VCR-treated worms on terminating exposure. However, CDDP exposure tended to reduce motility even 24 hr after terminating exposure. L-OHP exposure could decrease motility 2 hr after exposure, with a trend toward recovery 24 hr after terminating drug exposure. The findings of the present study revealed that C. elegans could exhibit neuropathy characteristics suggested to be similar to those observed in humans, indicating that this organism could be a suitable model to explore human CIPN.

Neuropilin-1 Expression Associates with Poor Prognosis in HNSCC and Elicits EGFR Activation upon CDDP-Induced Cytotoxic Stress.

Simple SummaryNRP-1, a co-receptor of the EGFR, represented an interesting candidate to investigate in HNSCC, as Cetuximab, in combination with radio and chemotherapy, provided the first targeted therapy scheme approved by the FDA as a standard of care for patients with recurrent or metastatic HNSCC. High levels of NRP-1 expression significantly correlated with a shorter overall survival in both Oral Squamous Cell Carcinoma and Oropharyngeal Squamous Cell Carcinoma diagnosed patients, suggesting a prognostic role for this protein. In HNSCC cell lines in vitro experiments, NRP-1 sustained EGFR activation upon CDDP exposure, together with activation of downstream MAPK/AKT pathways. Furthermore, NRP-1 modulated the responsiveness to CDDP treatment.Head and neck squamous cell carcinoma (HNSCC) includes a group of aggressive malignancies characterized by the overexpression of the epidermal growth factor receptor (EGFR) in 90% of cases. Neuropilin-1 (NRP-1) acts as an EGFR co-receptor, enhancing, upon ligand stimulation, EGFR signaling in several cellular models. However, NRP-1 remains poorly characterized in HNSCC. By utilizing in vitro cellular models of HNSCC, we report that NRP-1 is involved in the regulation of EGFR signaling. In fact, NRP-1 can lead to cisplatin-induced EGFR phosphorylation, an escape mechanism activated by cancer cells upon cytotoxic stress. Furthermore, we evaluated Neuropilin-1 staining in tissue samples of an HNSCC case series (n = 218), unraveling a prognostic value for the Neuropilin-1 tissue expression. These data suggest a potential role for NRP-1 in HNSCC cancer progression, expanding the repertoire of signaling in which NRP-1 is involved and eliciting the need for further investigations on NRP-1 as a suitable target for HNSCC novel therapeutic approaches.

Proteomic Analysis of the Non-genetic Response to Cisplatin in Lung Cancer Cells

Background: Drug resistance is the main cause of therapy failure in advanced lung cancer. Although non-genetic mechanisms play important roles in tumor chemoresistance, drug-induced epigenetic reprogramming is still poorly understood. Materials and Methods: The A549 cell line was used to generate cells with non-genetic resistance to cisplatin (CDDP), namely A549/CDDP cells. Bioorthogonal non-canonical amino acid tagging (BONCAT) and mass spectrometry were used to identify proteins modulated by CDDP in A549 and A549/CDDP cells. Results: Proteins related to proteostasis, telomere maintenance, cell adhesion, cytoskeletal remodeling, and cell redox homeostasis were found enriched in both cell lines upon CDDP exposure. On the other hand, proteins involved in drug response, metabolic pathways and mRNA processing and splicing were up-regulated by CDDP only in A549/CDDP cells. Conclusion: Our study revealed proteome dynamics involved in the non-genetic response to CDDP, pointing out potential targets to monitor and overcome epigenetic resistance in lung cancer.

Aconitase 2 sensitizes MCF-7 cells to cisplatin eliciting p53-mediated apoptosis in a ROS-dependent manner

Aconitase 2 (ACO2) belongs to the tricarboxylic acid (TCA) cycle, which represents a key metabolic hub for cellular metabolism that is frequently altered in cancer for satisfying bioenergetic and biosynthetic requirements of proliferating cells. The promotion of ACO2 activity in breast cancer cell lines was shown to slow down proliferation imposing a switch from aerobic glycolysis to oxidative metabolism. The alteration of metabolic pathways in cancer also impinges on the sensitivity to chemotherapeutic interventions. In this work, we evidence that the presence of ACO2 sensitizes cells to the treatment with the genotoxic agents cisplatin (CDDP) and doxorubicin activating the apoptotic cell death mechanism. This response was driven by the accumulation of reactive oxygen species (ROS) following both ACO2 overexpression and CDDP exposure that permit the stabilization/activation of p53 in nuclear and mitochondrial compartments. Collectively, our results highlight that in ACO2 overexpressing cells the promotion of mitochondrial metabolism accounts for increased ROS production that was buffered by p53 mitochondrial recruitment and autophagy induction. However, these systems are not able to counteract the CDDP-mediated oxidative stress that becomes the Achilles heel for increasing susceptibility to apoptotic cell death.

The Involvement of Pregnane X Receptor-regulated Pathways in the Antitumor Activity of Cisplatin.

Nuclear receptors regulate the expression of cellular transporters, which may be contributing factors for cisplatin (CDDP) resistance. This study aimed to clarify whether nuclear receptor ligands could be potentially used as drugs to overcome CDDP resistance. Caspase-3 activity was measured using a fluorogenic substrate. mRNA levels were determined using real-time polymerase chain reaction. Pregnane X receptor (PXR) showed an expression level change dependent on caspase-3 activation by CDDP in HepG2. Rifampicin, a PXR agonist, reduced the accumulation of CDDP and suppressed growth inhibition and caspase-3 activation in HepG2 after CDDP exposure. Leflunomide, a PXR antagonist, significantly enhanced caspase-3 activation by CDDP in HepG2 and CDDP-resistant HepG2/R. These results suggest that PXR can modify the antitumor activity of CDDP, presumably through regulating the expression of transporters, which control intracellular CDDP concentration. Thus, PXR antagonists can be further investigated as potential drugs capable of overcoming CDDP resistance.

The effect of cisplatin administration on certain trace elements homeostasis in rats and the protective effect of silver birch (Betula pendula) sap

BackgroundA clinically active structure with known antitumor activities is cisplatin (CDDP), but this it comes with toxicity characteristics which can be faded by the beneficial effects of Silver birch (Betula pendula) sap. ObjectiveWe aimed to assess the cisplatin activity on: Mn, Mg, Cu, Fe and Zn homeostasis in rats and to observe the effect of birch sap. MethodsHealthy Wistar rats (n = 10/group) were divided in four groups: Control: receiving 1 mL saline I.P. way + water; E1: cisplatin 20 mg kgbw−1, I.P.; E2: cisplatin 20 mg kgbw−1, I.P. + birch sap and Control sap group: 1 mL saline I.P. + birch sap. Blood was collected: at the trial’s start and after 48 h, and blood and organs (liver, kidney and spleen) for the cytoarchitecture investigation and readings were sampled after seven days. Samples were processed in nitric acid by microwave digestion and readings were completed by flame atomic absorption spectroscopy, the outcomes being statistically analyzed by ANOVA. ResultsCisplatin produced a significant imbalance in the trace elements homeostasis, the birch sap administration recovering them usual homeostasis status. Comparatively with the Control, rats exposed to cisplatin presented a not significant (p > 0.05) decrease of Zn (−26.74%) and Mg (−10.25%), a significant (p < 0.05) decrease of Cu (−27.73%) at 48 h, a highly significant (p < 0.01) decrease of Cu (−56.08%) and Fe (−85.35%) at seven days after administration and a not significant (p > 0.05) increase of Mn (+28.16%). Birch sap administration after Cisplatin was followed by restoration or nevertheless significant increase (p < 0.05) of the investigated trace elements Zn (+56.88% to 48 h/+89.94% after seven days), Mg (+26.86%/+95.74%), Cu (+23.13%/+74.56%), Fe (+39.64%/+440.11%) and Mn (+4.30%/+15.87%), suggesting them defence against cisplatin. Histology revealed the order of main altered organs after the CDDP exposure: kidney, spleen and liver. ConclusionsThe study recommended the important protective role of Betula pendula sap against diverse cisplatin deleterious side-effects.

Study of the protective effect of dexamethasone on cisplatin-induced ototoxicity in rats.

To evaluate the ability of dexamethasone to protect against cisplatin (CDDP)-induced ototoxicity. Male Wistar rats were divided into the following three groups: 1) Control (C): 6 animals received intraperitoneal (IP) saline solution, 8 ml/kg/day for four days; 2) C + CDDP: 11 animals received 8 ml/kg/day of IP saline and, 90 min after saline administration, 8 mg/kg/day of IP CDDP for four days; and 3) DEXA15 + CDDP: 11 animals received IP dexamethasone 15 mg/kg/day and, 90 min after dexamethasone administration, received 8 mg/kg/day of IP CDDP for four days. It was found that dexamethasone did not protect against weight loss in CDDP-exposed animals. The mortality rate was comparable with that previously reported in the literature. The auditory threshold of animals in the DEXA15 + CDDP group was not significantly altered after exposure to CDDP. The stria vascularis of animals in the DEXA15 + CDDP group was partially preserved after CDDP exposure. Dexamethasone at the dose of 15 mg/kg/day partially protected against CDDP-induced ototoxicity, based on functional evaluation by brainstem evoked response audiontry (BERA) and morphological evaluation by optical microscopy. However, dexamethasone did not protect against systemic toxicity.

Urinary metabolomics reveals the therapeutic effect of HuangQi Injections in cisplatin-induced nephrotoxic rats

The side effects of cisplatin (CDDP), notably nephrotoxicity, greatly limited its use in clinical chemotherapy. HuangQi Injections (HI), a commonly used preparation of the well-known Chinese herbal medicine Astragali radix, appeared to be promising treatment for nephrotoxicity without compromising the anti-tumor activity of CDDP. In this study, the urinary metabolomics approach using liquid chromatography time of flight mass spectrometry (LC-TOF/MS) was developed to assess the toxicity-attenuation effects and corresponding mechanisms of HI on CDDP-exposed rats. As a result, successive administration of HI significantly recovered the decline of body weight and downregulated the abnormal increase of serum creatinine and urea. HI partly restored the CDDP-induced alteration of metabolic profiling back into normal condition. Totally 43 toxicity-attenuation potential biomarkers were screened and tentatively identified, which were involved in important metabolic pathways such as amino acid metabolism, TCA cycle, fatty acid metabolism, vitamin B6 metabolism and purine metabolism. The results clearly revealed that HI could alleviate CDDP-induced nephrotoxicity and improve the disturbed metabolic balance induced by repeated CDDP exposure. The present study provided reliable evidence for the protective effect of HI on CDDP-induced toxicity with the multi-target pharmacological characteristics.

Dehydrobruceine B enhances the cisplatin-induced cytotoxicity through regulation of the mitochondrial apoptotic pathway in lung cancer A549 cells.

Dehydrobruceine B (DHB) is a quassinoid isolated from Brucea javanica. We have shown previously that DHB induced apoptosis on two kinds of lung cancer cell lines, A549 and NCI-H292. In the present study, we investigated the interactions of DHB and cisplatin (CDDP) on apoptotic-related cancer cell death. Synergistic effects on cell proliferation and apoptosis were observed when A549 cells were treated with DHB plus CDDP. DHB combined CDDP exposure increased depolarization of mitochondrial membrane potential (MMP) and release of cytochrome c from mitochondria into the cytoplasm. The combination treatment also enhanced protein expression of Bax, reduced the protein levels of Bcl-xL and Bcl-2, and increased the cleavage of caspase-3, caspase-9 and poly (ADP-ribose) polymerase (PARP). These results indicated that DHB sensitized A549 cells to cisplatin by regulating the mitochondrial apoptotic pathway. High constitutive expression of Nrf2 was found in A549 cells, which enhance the resistance of cancer cells to chemotherapeutic agents including cisplatin. DHB reduced the protein levels of Nrf2 and its target genes, which may contribute to the increase of intracellular ROS level, consequently, induced mitochondria apoptosis. These results generated a rationale for further investigation of DHB combined with CDDP as a potential therapeutic strategy in lung cancer.

1528P - Repeated exposure to cisplatin enhances NK cell-mediated cytotoxicity via up-regulation of NKG2D ligands in non-small cell lung cancer cells

Cisplatin (CDDP) is one of the key drugs for non-small cell lung cancer (NSCLC) and CDDP-resistant mechanisms have been investigated, while the role of immune cells on excluding CDDP-treated cancer cells is poorly understood. Here we demonstrate repeated exposure to CDDP enhances NK group 2 member D (NKG2D) ligands MHC class I-related chain A and B (MICA/B) and UL16 binding protein (ULBP)-2/5/6 in NSCLC cell lines while attenuates them in tumor tissue from patients with NSCLC. A549 cells were exposed to 10 µM of CDDP (A549-CR) at least thrice then possible influences of CDDP exposure on expressions of MICA/B and ULBP-2/5/6 were investigated by flow cytometry. NK cell-mediated cytotoxicity against A549-CR cells was assessed by LDH release assay and compared with original A549 cells. The expressions of NKG2D ligands in tissue samples from NSCLC patients who received CDDP-base chemotherapy were also evaluated using immunohistochemical reactions. Basal expression of MICA/B and ULBP-2/5/6 were clearly upregulated in A549-CR cells compared with original A549 cells. As expected, NK cell-mediated cytotoxicity was enhanced against A549-CR cells compared with A549 cells, and this enhancement depended on NKG2D-NKG2D ligands interaction. On the other hand, the expression of MICA/B and ULBP-2/5/6 were lower in residual tumor than in pre-treated samples from patients with NSCLC. Repeated CDDP exposure enhances the expression of NKG2D ligands in A549 cell line, resulted in enhanced NK cell-mediated cytotoxicity in vitro. On the other hand, repeated CDDP exposure attenuated the expression of NKG2D ligands in patients with NSCLC, suggested that the residual tumor was the result of tumor immunoescape from NK cells.

Toxic effects of cisplatin cytostatic drug in mussel Mytilus galloprovincialis

Antineoplastic drugs used in chemotherapy were detected in aquatic environment: despite the very low concentrations (ng L−1 to ug L−1), due to their potent mechanism of action they could have adverse effects on non-target aquatic organisms particularly under chronic exposure. Cisplatin (CDDP) is one of the most effective anticancer drug currently in use but information on its ecotoxicological effects is very limited. In this study, Mytilus galloprovincialis was used to investigate the toxic effects related to CDDP exposure. Mussels were exposed to cisplatin (100 ng L−1) for 14 days: antioxidant (superoxide dismutase, catalase, total and selenium-dependent glutathione peroxidase) and phase II (glutathione-S-transferase) enzymes activities, oxidative damage (lipid peroxidation), genotoxicity (DNA damage) and neurotoxicity (acetylcholinesterase) was evaluated. Results indicate that CDDP at tested concentration induce changes in the antioxidant capacity, oxidative stress in target organs (digestive gland and gills) as well as DNA damage in mussel hemocytes and neurotoxicity representing a risk for non-target organisms.

O(6) -methylguanine DNA methyltransferase repairs platinum-DNA adducts following cisplatin treatment and predicts prognoses of nasopharyngeal carcinoma.

Cisplatin (CDDP) is an important anti-cancer drug commonly used in various human cancers, including nasopharyngeal carcinoma (NPC). How to overcome the drug resistance of CDDP provides opportunities to improve clinical outcomes of NPC. O(6) -methylguanine-DNA methyltransferase (MGMT) has been well-characterized to be a therapeutic determinant of O(6) -alkylguanine alkylating drugs. However, the underlying mechanism and clinical relevance between MGMT and CDDP remain poorly defined in NPC. In this study, we showed that MGMT-proficient cells were highly resistant to the cytotoxic effects of CDDP as compared to MGMT-deficient cells. Further studies showed that the platinum level of DNA after CDDP exposure was significantly lower in MGMT-proficient cells than in MGMT-deficient cells. Host cell reactivation assay revealed that MGMT protected NPC cells from CDDP-induced DNA damage by enhancing DNA repair capacity. Importantly, we demonstrated for the first time that MGMT protein directly bound to CDDP-induced DNA damages. Subsequently, CDDP-bound MGMT protein became ubiquitinated and was degraded through ubiquitin-mediated proteasome system. We further analyzed the relationship between MGMT expression and clinical survivals in a cohort of 83 NPC patients. NPC patients who received CDDP-based concurrent chemoradiotherapy (CCRT), with high MGMT expression level, exhibited shorter progression-free survival (PFS; p = 0.022) and overall survival (OS; p = 0.015), than patients with low MGMT expression level. Furthermore, high MGMT expression level remained to be an independent prognostic factor for worse PFS (p = 0.01, hazard ratio 2.23) and OS (p = 0.018, hazard ratio 2.14). Our findings suggest that MGMT protein is important to determine the efficacy of CDDP in NPC.

DR-04 * VALPROIC ACID AND HEDGEHOG PATHWAY: A POSSIBLE DRUG RESISTANCE MECHANISM IN MEDULLOBLASTOMA?

BACKGROUND: Medulloblastoma (MB) is a malignant neuroepithelial embryonal tumor of cerebellum. In children, they comprise the most frequent embryonal brain tumor. This study aim to investigate the role of valproic acid (VA) and cisplatin (CDDP) in the cytotoxicity, viability, and expression of hedgehog pathway (HH) in MB DAOY cell line. METHODS: The treatment of DAOY cells was distributed in four groups: (1) VA single, (2) CDDP single, (3) VA sensibilization + CDDP, (4) untreated. Cell viability was measured by Presto Blue assay, qPCR was performed to quantify HH genes and two PTCH1 punctual mutations were investigated by direct sequencing. RESULTS: VA and CDDP affected the viability of DAOY cell line (IC50= 6mM and 10mM, respectively). VA sensibilization followed by CDDP exposure (group 3) caused the most significant reduction of cell viability. Interestingly, we observed higher expression levels of PTCH1, SMO, GLI1 and GLI2 genes in the cells treated with VA (single or combined), than the cells submitted to the others treatments (groups 2 and 4). We identified the presence of H408N mutation, in PTCH1 gene in DAOY cells. CONCLUSIONS: The HH pathway is considered to be crucially involved in the development of MB. Our study showed that MB cells resistant to treatment with VA, single or combined, presented high expression of HH genes. Recent studies have demonstrated that the chronic use of VA is associated with reactivation of AKT pathway, which may be involved in resistance development. Additionally, AKT activates HH pathway in an independent-manner. In this way, we suggest that the resistance of MB cells submitted to VA treatment may be related to the activation of HH pathway via AKT. The MB treatment with VA should be cautious and deserves further investigation about the role of this HDAC inhibitor in the drug resistance development in MB.

Vasohibin 2 Decreases the Cisplatin Sensitivity of Hepatocarcinoma Cell Line by Downregulating p53

Hepatocellular carcinoma (HCC) is a prevalent problem worldwide. Chemotherapy, especially cisplatin (CDDP)-based systemic chemotherapy, is the best option for advanced liver cancer. However, CDDP resistance is becoming common and hindering the clinical application of CDDP. Meanwhile, no consensus has been reached regarding the chemotherapeutic use of vasohibin 2 (VASH2), which promotes the angiogenesis and proliferation of cancer cells. In this work, a tissue microarray was used to observe VASH2 and its possible role in cancer treatment. Results showed that VASH2 was highly expressed in HCC tissues and was significantly correlated with cancer differentiation. To further investigate the efficacy and mechanism of the combination of VASH2 with anti-cancer drugs in liver cancer cells, we stably built VASH2 overexpression and knockdown cell lines. We found that VASH2 can influence the CDDP sensitivity and that the cell overexpression of VASH2 had a higher cell viability and lower apoptosis rate after CDDP exposure. We also observed that VASH2 overexpression downregulated wild-type p53, as well as suppressed the expression of the pro-apoptotic protein BCL2-associated X protein (Bax) and cleaved caspase-3 (CC-3) after treatment by CDDP. Conversely, the knockdown of VASH2 significantly inhibited these effects. In an in vivo chemosensitivity study, nude mice were subcutaneously injected with tumor cells and received CDDP treatment through intraperitoneal administration every 3 days. We found that VASH2 knockdown markedly limited the tumor growth and enhanced the CDDP toxicity and apoptosis of tumor cells. Western blot analysis revealed that tumor cells with downregulated VASH2 had a higher expression of wild-type p53, Bax, and CC-3 than control cells. Overall, our results indicated the novel roles of VASH2 in the chemoresistance of hepatocarcinoma cells to CDDP and suggested that VASH2 may be a promising anticancer target.