Cisplatin-resistant Cell Lines Research Articles

Triple Combination of Entinostat, a Bromodomain Inhibitor, and Cisplatin Is a Promising Treatment Option for Bladder Cancer

Background/Objectives. Cisplatin is part of the first-line treatment of advanced urothelial carcinoma. Cisplatin resistance is a major problem but may be overcome by combination treatments such as targeting epigenetic aberrances. Here, we investigated the effect of the class I HDACi entinostat and bromodomain inhibitors (BETis) on the potency of cisplatin in two pairs of sensitive and cisplatin-resistant bladder cancer cell lines. Cisplatin-resistant J82cisR and T24 LTT were 3.8- and 24-fold more resistant to cisplatin compared to the native cell lines J82 and T24. In addition, a hybrid compound (compound 20) comprising structural features of an HDACi and a BETi was investigated. Results. We found complete (J82cisR) or partial (T24 LTT) reversal of chemoresistance upon combination of entinostat, JQ1, and cisplatin. The same was found for the BETis JQ35 and OTX015, both in clinical trials, and for compound 20. The combinations were highly synergistic (Chou Talalay analysis) and increased caspase-mediated apoptosis accompanied by enhanced expression of p21, Bim, and FOXO1. Notably, the combinations were at least 4-fold less toxic in non-cancer cell lines HBLAK and HEK293. Conclusions. The triple combination of entinostat, a BETi, and cisplatin is highly synergistic, reverses cisplatin resistance, and may thus serve as a novel therapeutic approach for bladder cancer.

Hydrazide-Based Class I Selective HDAC Inhibitors Completely Reverse Chemoresistance Synergistically in Platinum-Resistant Solid Cancer Cells.

In this work, we have synthesized a set of peptoid-based histone deacetylase inhibitors (HDACi) with a substituted hydrazide moiety as zinc-binding group. Subsequently, all compounds were evaluated in biochemical HDAC inhibition assays and for their antiproliferative activity against native and cisplatin-resistant cancer cell lines. The hydrazide derivatives with a propyl or butyl substituent (compounds 5 and 6) emerged as the most potent class I HDAC selective inhibitors (HDAC1-3). Further, compounds 5 and 6 outperformed entinostat in cytotoxicity assays and were able to reverse chemoresistance in cisplatin-resistant A2780 (ovarian) and Cal27 (head-neck) cancer cell lines. Moreover, the hydrazide derivatives 5 and 6 showed strong synergism with cisplatin (combination indices <0.2), again outperforming entinostat, and increased DNA damage, p21, and pro-apoptotic BIM expression, leading to caspase-mediated apoptosis and cell death. Thus, compounds 5 and 6 represent promising lead structures for developing new HDACi capable of reversing chemoresistance in cisplatin resistant cancer cells.

Inhibition of Epithelial-Mesenchymal Transition and Migration in Cisplatin-resistant Cancer Through Combined Treatment With Cisplatin and SH003.

This study investigated the synergistic effects of combining cisplatin and SH003 treatment on the viability, apoptosis, cytotoxicity, migration and epithelial-mesenchymal transition (EMT) in cisplatin-resistant cancer cell lines YD-8/CIS, YD-9/CIS and YD-38/CIS. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to assess cell viability, while trypan blue exclusion assay was used to evaluate cytotoxicity. Flow cytometry and western blot analysis measured apoptotic cell death. Wound-healing assays evaluated cell migration and EMT markers. Combination index (CI) plots were used to evaluate the combinatory effects of the treatment. Combination therapy significantly reduced cell viability more effectively than each agent alone, as demonstrated by the MTT assay, with CI plots confirming notable synergism. Trypan blue exclusion assays indicated increased cell death and cytotoxicity in combination treatment than in both monotherapies, although the increase was not significant. Flow cytometry and western blot analysis revealed no significant synergistic effect on apoptotic cell death. However, wound-healing assays revealed that the combination of cisplatin and SH003 significantly inhibited cell migration and regulated EMT markers, indicating the potential reversal of EMT. Combining cisplatin and SH003 therapy may potentially be a more effective strategy for treating cisplatin-resistant cancer by increasing cytotoxicity and inhibiting metastasis. Further research is required to elucidate the underlying mechanisms and evaluate the in vivo efficacy of this combination therapy.

Pd(II)/1,10-phenanthroline complexes bearing arene ligands: On the role of N- vs O-coordination to tune their cellular activity and binding ability towards DNA and RNA

Three Pd(II)-based complexes of 1,10-phenanthroline and N- or O-coordinating ligands have been synthesised and tested with different relevant biosubstrates like double-stranded DNA, double and triple helix of RNA, DNA G-quadruplexes of different conformations and bovine serum albumin. Here a correlation between N- vs O-coordinating elements and binding mechanism emerged, where the N-coordinating ligands proved to be the most promising. These outcomes were confirmed also in the cellular experiments. The Pd(II) complex with naphthalene-1,8-diamine is the one that is able to be carried by BSA, to strongly bind nucleic acids, to produce reactive oxygen species (ROS) and to show the best cellular performances (poorly toxic towards healthy cells and highly toxic against the cisplatin-resistant cancer cell line). On the opposite, the complex with benzene-1,2-diolate may be sequestered by BSA, weakly binds nucleic acids, does not produce ROS and shows poor cellular activity. The complex with benzene-1,2-diamine stays in between. Other mechanistic details are discussed which show that the biophysical behaviour is the sum of the contribution of aromaticity, charge and N- or O-coordination.

T-Box Transcription Factor 2 Mediates Chemoresistance of Endometrial Cancer via Regulating FSP1-involved Ferroptosis.

Chemotherapy is increasingly being used in the first-line treatment of endometrial cancer (EC) patients. However, chemoresistance seriously affects its efficacy. Understanding the underlying molecular mechanisms is critical for EC treatment. We explored the regulatory role of T-Box transcription factor 2 (TBX2)-ferroptosis suppressor protein 1 (FSP1) axis in ferroptosis and chemoresistance of EC. Cisplatin-resistant cell line Ishikawa/DDP cells were utilized to generate TBX2 and FSP1 overexpression and knockdown stable cell lines by using lentivirus infection and puromycin selection. Cell viability and ferroptosis status were evaluated in EC cells with or without Cisplatin and/or FSP1 inhibitor (iFSP1) using CKK-8, lipid peroxidation, malondialdehyde, and lactate dehydrogenase release assays. Endometrial carcinoma xenograft mouse model was established to further explore the function of TBX2-FSP1 axis on ferroptosis and tumor progression in EC. TBX2 suppressed Cisplatin-induced ferroptosis through up-regulating FSP1 expression level in EC cells. On the contrary, knockdown of TBX2 reduced FSP1 expression and significantly promoted Cisplatin-induced ferroptosis. TBX2 or FSP1 overexpression and knockdown promote and inhibit EC tumor growth under Cisplatin treatment, respectively. Interestingly, silence FSP1 could reverse TBX2-mediated ferroptosis inhibition and tumor-promoting effect. TBX2-FSP1 axis inhibits ferroptosis and enhances the Cisplatin resistance, which will provide an important theoretical basis and potential solution for the clinical treatment of EC.

In vitro anticancer activity of a head-to-toe constructed heterobimetallic [CoFeL]2+ metallocylinder

ABSTRACT [M2L3]-type metallo-supramolecular architectures (MSAs) are widely explored for their biological activity, whereas data on non-symmetric, heterobimetallic [MM’L3] structures is comparatively rare. [M2L3] compounds are known to form helicates and/or mesocates. Here, we report the self-assembly of a discrete non-symmetrical, heterobimetallic MSA by combination of an amine-functionalised cobalt(III)-tris((picolinamido)ethyl)amine (PICTREN) base unit with FeCl2 and 2,2’-bipyridine-5-carboxaldehyde. NMR spectroscopy in tandem with computational studies revealed the formation of a mesocate rather than a helicate. The ability of the heteromesocate to bind to DNA was examined by gel electrophoresis with pUC19 plasmid DNA, which showed DNA binding although longer incubation periods were required than found for a known DNA-interacting helicate. The mesocate displayed promising antiproliferative activity in cancer cells, including a cisplatin-resistant cell line, with IC50 values in the 17–26 μM range. Lower biological activity of the mesocate compared to a metallocylinder reference and cisplatin may be explained by differences in the DNA interactions. This work further supports efforts to establish methods with which to construct heterobimetallic complexes, establishing the utility of the self-assembly method in [M2L3]-type assemblies using the cobalt(III)-PICTREN platform as a robust building block towards more complex assemblies of the [MM’L]-type.

Silencing Nrf2 in cisplatin resistant non-small cell lung cancer cells augments sensitivity towards EGFR inhibitor

Recently, non-small cell lung cancer (NSCLC) has been the prime concern of cancer clinicians due to its high mortality rate worldwide. Cisplatin, a platinum derivative, has been used as a therapeutic option for treating metastatic NSCLC for several years. However, acquired, or intrinsic drug resistance to Cisplatin is the major obstacle to the successful treatment outcome of patients. Dysregulation of Nrf2 (nuclear factor erythroid 2-related factor 2) and EGFR (epidermal growth factor receptor) signaling have been associated with cellular proliferation, cancer initiation, progression and confer drug resistance to several therapeutic agents including Cisplatin in various cancers. To dissect the molecular mechanism of EGFR activation in resistant cells, we developed Cisplatin-resistant (CisR) human NSCLC cell lines (A549 and NCIH460) with increasing doses of Cisplatin treatment over a 3-month period. CisR cells demonstrated increased proliferative capacity, clonogenic survivability and drug efflux activity compared to the untreated parental (PT) cells. These resistant cells also showed higher levels of Nrf2 and EGFR expression. Here, we found that Nrf2 upregulates both basal and inducible expression of EGFR in these CisR cells at the transcriptional level. Moreover, genetic inhibition of Nrf2 with siRNA in CisR cells showed increased sensitivity towards the EGFR tyrosine kinase inhibitor (TKIs), AG1478. Our study, therefore suggests the use of Nrf2 inhibitors in combinatorial therapy with EGFR TKIs for the treatment of resistant NSCLC.

A novel combinatory treatment against a CDDP-resistant non-small cell lung cancer based on a Ruthenium(II)-cyclopentadienyl compound

The therapeutic approach to many solid tumors, including non-small cell lung cancer (NSCLC), is mainly based on the use of platinum-containing anticancer agents and is often characterized by acquired or intrinsic resistance to the drug. Therefore, the search for safer and more effective drugs is still an open challenge.Two organometallic ruthenium(II)-cyclopentadienyl compounds [Ru(η5-C5H4CHO)(Me2bipy)(PPh3)]+ (RT150) and [Ru(η5-C5H4CH2OH)(Me2bipy)(PPh3)][CF3SO3] (RT151) were tested against a panel of cisplatin-resistant NSCLC cell lines and xenografts. They were more effective than cisplatin in inducing oxidative stress and DNA damage, affecting the cell cycle and causing apoptosis. Importantly, they were found to be inhibitors of drug efflux transporters. Due to this property, the compounds significantly increased the retention and cytotoxicity of cisplatin within NSCLC cells. Notably, they did not display high toxicity in vitro against non-transformed cells (red blood cells, fibroblasts, bronchial epithelial cells, cardiomyocytes, and endothelial cells). Both compounds induced vasorelaxation and reduced endothelial cell migration, suggesting potential anti-angiogenic properties. RT151 confirmed its efficacy against NSCLC xenografts resistant to cisplatin. Either alone or combined with low doses of cisplatin, RT151 showed a good biodistribution profile in the liver, kidney, spleen, lung, and tumor. Hematochemical analysis and post-mortem organ pathology confirmed the safety of the compound in vivo, also when combined with cisplatin.To sum up, we have confirmed the effectiveness of a novel class of drugs against cisplatin-resistant NSCLC. Additionally, the compounds have a good biocompatibility and safety profile.

Cabazitaxel as a promising therapy for cisplatin-resistant bladder cancer: a preliminary study.

Bladder cancer is a common malignancy worldwide, posing a substantial healthcare challenge. Current standard treatment regimens are primarily based on cisplatin, but their success is often limited by cisplatin resistance and associated toxicities. Therefore, there is an urgent need to develop effective and less toxic therapies as alternatives to cisplatin. We screened the activity of FDA-approved anti-cancer drugson a panel of cisplatin-resistant bladder cancer cell lines. Based on initial responses, cabazitaxel was selected for further evaluation of its inhibitory effects on the phenotypic properties of these cells. Cabazitaxel, primarily used for metastatic castration-resistant prostate cancer, demonstrated remarkable efficacy in inhibiting colony formation, proliferation, and migration of cisplatin-resistant bladder cancer cells. This study highlights the potential of drug repurposing as a cost-effective and efficient strategy to overcome drug resistance in bladder cancer.

Circular RNA circ_ARHGEF28 inhibits MST1/2 dimerization to suppress Hippo pathway to induce cisplatin resistance in ovarian cancer

BackgroundCisplatin is integral to ovarian cancer treatment, yet resistance to this drug often results in adverse patient outcomes. The association of circular RNA (circRNA) with cisplatin resistance in ovarian cancer has been observed, but the mechanisms governing this relationship require further elucidation.MethodsHigh-throughput sequencing was utilized to profile circRNA expression in cisplatin-resistant ovarian cancer cells. Gain-and-loss-of-function experiments assessed the impact on cisplatin sensitivity, both in vitro and in vivo. Fluorescence in situ hybridization was conducted to determine the cellular distribution of circRNAs, and RNA pulldown and immunoprecipitation experiments were performed to identify associated binding proteins.ResultsThe study revealed that circ_ARHGEF28 is overexpressed in certain cisplatin-resistant ovarian cancer tissues and cell lines, and is associated with reduced progression-free survival in patients. It was observed that circ_ARHGEF28 contributes to cisplatin resistance in ovarian cancer models, both in vitro and in vivo. Importantly, circ_ARHGEF28 was found to interact directly with MST1/2, inhibiting the SARAH coiled-coil binding domains and consequently deactivating the Hippo pathway.ConclusionThis investigation identifies circ_ARHGEF28 as a novel circRNA that contributes to cisplatin resistance in ovarian cancer by suppressing the Hippo pathway. Therapeutic strategies targeting circ_ARHGEF28 may offer a potential avenue to mitigate cisplatin resistance in ovarian cancer treatment.

Comprehensive analysis of hub genes associated with cisplatin-resistance in ovarian cancer and screening of therapeutic drugs through bioinformatics and experimental validation

BackgroundTo identify key genes associated with cisplatin resistance in ovarian cancer, a comprehensive analysis was conducted on three datasets from the GEO database and through experimental validation.MethodsGene expression profiles were retrieved from the GEO database. DEGs were identified by comparing gene expression profiles between cisplatin-sensitive and resistant ovarian cancer cell lines. The identified genes were further subjected to GO, KEGG, and PPI network analysis. Potential inhibitors of key genes were identified through methods such as LibDock nuclear molecular docking. In vitro assays and RT-qPCR were performed to assess the expression levels of key genes in ovarian cancer cell lines. The sensitivity of cells to chemotherapy and proliferation of key gene knockout cells were evaluated through CCK8 and Clonogenic assays.ResultsResults showed that 12 genes influenced the chemosensitivity of the ovarian cancer cell line SKOV3, and 9 genes were associated with the prognosis and survival outcomes of ovarian cancer patients. RT-qPCR results revealed NDRG1, CYBRD1, MT2A, CNIH3, DPYSL3, and CARMIL1 were upregulated, whereas ERBB4, ANK3, B2M, LRRTM4, EYA4, and SLIT2 were downregulated in cisplatin-resistant cell lines. NDRG1, CYBRD1, and DPYSL3 knock-down significantly inhibited the proliferation of cisplatin-resistant cell line SKOV3. Finally, photofrin, a small-molecule compound targeting CYBRD1, was identified.ConclusionThis study reveals changes in the expression level of some genes associated with cisplatin-resistant ovarian cancer. In addition, a new small molecule compound was identified for the treatment of cisplatin-resistant ovarian cancer.

The Induction of G2/M Phase Cell Cycle Arrest and Apoptosis by the Chalcone Derivative 1C in Sensitive and Resistant Ovarian Cancer Cells Is Associated with ROS Generation.

Ovarian cancer ranks among the most severe forms of cancer affecting the female reproductive organs, posing a significant clinical challenge primarily due to the development of resistance to conventional therapies. This study investigated the effects of the chalcone derivative 1C on sensitive (A2780) and cisplatin-resistant (A2780cis) ovarian cancer cell lines. Our findings revealed that 1C suppressed cell viability, induced cell cycle arrest at the G2/M phase, and triggered apoptosis in both cell lines. These effects are closely associated with generating reactive oxygen species (ROS). Mechanistically, 1C induced DNA damage, modulated the activity of p21, PCNA, and phosphorylation of Rb and Bad proteins, as well as cleaved PARP. Moreover, it modulated Akt, Erk1/2, and NF-κB signaling pathways. Interestingly, we observed differential effects of 1C on Nrf2 levels between sensitive and resistant cells. While 1C increased Nrf2 levels in sensitive cells after 12 h and decreased them after 48 h, the opposite effect was observed in resistant cells. Notably, most of these effects were suppressed by the potent antioxidant N-acetylcysteine (NAC), underscoring the crucial role of ROS in 1C-induced antiproliferative activity. Moreover, we suggest that modulation of Nrf2 levels can, at least partially, contribute to the antiproliferative effect of chalcone 1C.

Targeting metabolic reprogramming to overcome drug resistance in advanced bladder cancer: insights from gemcitabine- and cisplatin-resistant models.

Gemcitabine plus cisplatin (GC) combination chemotherapy is the primary treatment for advanced bladder cancer (BC) with unresectable or metastatic disease. However, most cases develop resistance to this therapy. We investigated whether drug resistance could be targeted through metabolic reprogramming therapies. Metabolomics analyses in our lab's gemcitabine- and cisplatin-resistant cell lines revealed increased phosphoglycerate dehydrogenase (PHGDH) expression in gemcitabine-resistant cells compared with parental cells. Isocitrate dehydrogenase 2 (IDH2) gain of function stabilized hypoxia-inducible factor1α (HIF1α) expression, stimulating aerobic glycolysis. In gemcitabine-resistant cells, elevated fumaric acid suppressed prolyl hydroxylase domain-containing protein 2/Egl nine homolog 1 (PHD2) and stabilized HIF1α expression. PHGDH downregulation or inhibition in gemcitabine-resistant BC cells inhibited their proliferation, migration, and invasion. Cisplatin-resistant cells showed elevated fatty acid metabolism, upregulating fatty acid synthase (FASN) downstream of tyrosine kinase. Using the fibroblast growth factor receptor (FGFR) tyrosine kinase inhibitor erdafitinib, we inhibited malonyl-CoA production, which is crucial for fatty acid synthesis, and thereby suppressed upregulated HIF1α expression. Combination treatment with NCT503 and erdafitinib synergistically suppressed tumor cell proliferation and induced apoptosis in vitro and in vivo. Understanding these mechanisms could enable innovative BC therapeutic strategies to be developed.

P27Kip1 and cytoplasmic pSer10p27 are promising biomarkers for predicting prognosis and chemotherapy response in ovarian cancer.

The biological function of p27Kip1 largely depends on its subcellular localization and phosphorylation status. Different subcellular localizations and phosphorylation statuses of p27Kip1 may represent distinct clinical values, which are unclear in ovarian cancer. This study aimed to elucidate different subcellular localizations of p27Kip1 and pSer10p27 in predicting prognosis and chemotherapy response in ovarian cancer. Meta-analyses were executed to evaluate the association of p27Kip1 and phosphorylated p27Kip1 with the prognosis of ovarian cancer patients. The expression levels and patterns of p27Kip1 and pSer10p27 were evaluated by immunohistochemistry. The correlations between different p27Kip1 states, clinicopathological features, and prognosis were analyzed. p27Kip1 and pSer10p27 expression levels in cisplatin-sensitive and cisplatin-resistant ovarian cancer cell lines were detected using WB. KEGG analysis and WB were performed to evaluate the pathways in which p27Kip1 was involved. Meta-analyses showed that p27Kip1 was associated with significantly better overall survival (OS) in ovarian cancer (HR=2.14; 95% CI [1.71-2.68]) and pSer10p27 was associated with significantly poor OS in mixed solid tumors (HR=2.56; 95% CI [1.76-3.73]). In our cohort of ovarian cancer patients, low total p27Kip1 remained independent risk factors of OS (HR=2.097; 95% CI [1.121-3.922], P=0.021) and PFS (HR=2.483; 95% CI [1.364-4.518], P=0.003), while low cytoplasmic pSer10p27 had independent protective effects in terms of OS (HR=0.472; 95% CI [0.248-0.898], P=0.022) and PFS (HR=0.488; 95% CI [0.261-0.910], P=0.024). Patients with low total p27Kip1/pSer10p27 and low nuclear p27Kip1 had worse chemotherapy responses, while patients with low cytoplasmic pSer10p27 expression had better chemotherapy responses. The protein levels of p27Kip1 and pSer10p27 were significantly reduced in the cisplatin-resistant cell lines SKOV3-cDDP and A2780-cDDP, and the level of p27Kip1/pSer10p27 was subjective to Akt activation. The present study demonstrates that p27Kip1 and cytoplasmic pSer10p27 are promising biomarkers for predicting prognosis and chemotherapy response in ovarian cancer.

CDKN2A inhibited ferroptosis through activating JAK2/STAT3 pathway to modulate cisplatin resistance in cervical squamous cell carcinoma.

Cervical squamous cell carcinoma (CESC) is a significant threat to women's health. Resistance to cisplatin (DDP), a common treatment, hinders the therapeutic efficacy. Understanding the molecular basis of DDP resistance in CESC is imperative. Cyclin-dependent kinase inhibitor 2A (CDKN2A) expression was evaluated through quantitative real-time-PCR and western blot in clinical samples from 30 CESC patients and human cervical epithelial cells and CESC cell lines (SiHa, C33A, and Caski). It was also evaluated through bioinformatics analysis in Timer, Ualcan, and GEPIA database. Cell viability was detected by CCK-8. Apoptosis was detected by Calcein AM/PI assay. Lipid reactive oxygen species (ROS), malondialdehyde, glutathione, Fe 2+ , and iron level were detected by kits. Protein level of JAK2, STAT3, p-JAK2, p-STAT3, ACSL4, GPX4, SLC7A11, and FTL were detected by western blot. In CESC, elevated CDKN2A expression was observed. Cisplatin exhibited a dual effect, inhibiting cell proliferation and inducing ferroptosis in CESC. CDKN2A knockdown in a cisplatin-resistant cell line suppressed proliferation and induced ferroptosis. Moreover, CDKN2A was identified as an inhibitor of erastin-induced ferroptosis. Additionally, targeting the JAK2/STAT3 pathway enhanced ferroptosis in cisplatin-resistant cells. CDKN2A could inhibit ferroptosis in CESC through activating JAK2/STAT3 pathway to modulate cisplatin resistance.

Capsaicin reverses cisplatin resistance in tongue squamous cell carcinoma by inhibiting the Warburg effect and facilitating mitochondrial-dependent apoptosis via the AMPK/AKT/mTOR axis.

Cisplatin is commonly used for the chemotherapy of tongue squamous cell carcinoma (TSCC); however, adverse side effects and drug resistance impact its therapeutic efficacy. Capsaicin is an active ingredient in chili peppers that exerts antitumor effects, whether it exerts antitumor effects on cisplatin-resistant cells remains unknown. Therefore, in this study, we investigated the effect of capsaicin on cisplatin resistance in TSCC cells and explored the underlying mechanisms. A cisplatin-resistant TSCC cell line was established by treated with increasing cisplatin concentrations. Combined treatment with cisplatin and capsaicin decreased the glucose consumption and lactate dehydrogenase activity and increased the adenosine triphosphate production both in vitro and in vivo, suggesting the inhibition of the Warburg effect. Moreover, this combined treatment induced cell apoptosis and significantly upregulated the levels of proapoptotic proteins, such as Bax, cleaved caspase-3, -7, and -9, and apoptosis-inducing factor. In contrast, levels of the antiapoptotic protein, Bcl-2, were downregulated. Additionally, LKB1 and AMPK activities were stimulated, whereas those of AKT and mTOR were suppressed. Notably, AMPK knockdown abolished the inhibitory effects of capsaicin and cisplatin on the AKT/mTOR signaling pathway and Warburg effect. Overall, combined treatment with capsaicin and cisplatin reversed cisplatin resistance by inhibiting the Warburg effect and facilitating mitochondrial-dependent apoptosis via the AMPK/AKT/mTOR axis. Our findings suggest combination therapy with capsaicin and cisplatin as a potentially novel strategy and highlight capsaicin as a promising adjuvant drug for TSCC treatment.

Plasmonic laser-responsive BioDissolve 3D-printed graphene@cisplatin-implant for prevention of post-surgical relapse of oral cancer

The development of chemoresistance is a major obstacle in post-surgical adjuvant therapy of cancer, leading to cancer cell survival, recurrence, and metastasis. This study reports a 3D-printed plasmonic implant developed for the post-surgical adjuvant therapy of cisplatin-resistant cancer cells to prevent relapse. The implant was printed using optimized biomaterial ink containing biodegradable polymers [poly(L-lactide) and hydroxypropyl methylcellulose] blended suitably with laser-responsive graphene and chemo drug (Cisplatin). The irradiation of scar-driven 3D-printed implant with a laser stimulates graphene to generate a series of hyperthermia events leading to photothermolysis of cisplatin-resistant cancer cells under the combined influence of sustained cisplatin release. The developed personalized implant offers pH-responsive sustained drug release for 28 days. The implant exhibited acceptable biophysical properties (Tensile strength: 3.99 ± 0.15 MPa; modulus: 81 ± 9.58 MPa; thickness: 110 μm). The 3D-printed implant effectively reverses the chemoresistance in cisplatin-resistant 3D spheroid tumor models. Cytotoxicity assay performed using cisplatin-resistant (CisR) cell line revealed that the cell viability was reduced to 39.80 ± 0.68 % from 61.37 ± 0.98 % in CisR tumor spheroids on combined chemo-photothermal therapy. The combination therapy reduced the IC50 value from 71.05 μM to 48.73 μM in CisR spheroids. Apoptosis assay revealed an increase in the population of apoptotic cells (35.45 ± 1.56 % →52.53 ± 2.30 %) on combination therapy. A similar trend was observed in gene expression analysis, where the expression of pro-apoptotic genes Caspase 3 (3.73 ± 0.04 fold) and Bcl-2-associated X protein (BAX) (3.35 ± 0.02 fold) was increased on combination therapy. This 3D-printed, biodegradable implant with chemo-combined thermal ablating potential may provide a promising approach for the adjuvant treatment of resistant cancer.

Identification of a cisplatin resistant-based prognostic immune related gene signature in MIBC

Cisplatin resistance plays a significant role in the dismal prognosis and progression of muscle-invasive bladder cancer (MIBC). However, the strategies to predict prognosis and cisplatin resistance are inefficient, and it remains unclear whether cisplatin resistance is associated with tumor immunity. In this study, we integrated the transcriptional data from cisplatin-resistant cell lines and a TCGA-MIBC cohort to establish cisplatin-resistance-related cluster classification and a cisplatin-resistance-related gene risk score (CRRGRS). Kaplan–Meier survival curves showed that compared with those in low CRRGRS group, MIBC patients belonging to high CRRGRS group had worse prognosis in TCGA-MIBC cohort and external GEO cohorts. Meanwhile, CRRGRS was able to help forecast chemotherapy and immunotherapy response of MIBC patients in the TGCA cohort and IMvigor210 cohort. Moreover, compared with the low CRRGRS group, the high CRRGS group possessed a relatively immunosuppressive “cold tumor” phenotype with a higher tumor immune dysfunction and exclusion (TIDE) score, ESTIMATE score, stromal score and immune score and a lower immunophenoscore (IPS) score. The upregulated expression levels of immune checkpoint genes, including PD-1, PD-L1 and CTLA4, in the high CRRGRS group also further indicated that a relative immunosuppressive tumor microenvironment may exist in MIBC patients belonging to high CRRGRS group. In addition, we integrated CRRGRS and clinical characteristics with prognostic value to develop a nomogram, which could help forecast overall survival of MIBC patients. Furthermore, DIAPH3 was identified as a regulator of proliferation and cisplatin resistance in MIBC. The expression of DIAPH3 was increased in cisplatin-resistant cell lines and chemotherapy-unsensitive people. Further mechanism exploration revealed that DIAPH3 facilitated tumor proliferation and cisplatin resistance by regulating the NF-kB and epithelial-mesenchymal transition (EMT) pathways. In conclusion, the comprehensive investigations of CRRGRS increased the understanding of cisplatin resistance and provided promising insights to restrain tumor growth and overcome chemoresistance by targeting DIAPH3.

(Pentamethylcyclopentadienyl)chloridoiridium(III) Complex Bearing Bidentate Ph2PCH2CH2SPh-κP,κS Ligand.

The (pentamethylcyclopentadienyl)chloridoiridium(III) complex bearing a κP,κS-bonded Ph2PCH2CH2SPh ligand ([Ir(η5-C5Me5)Cl(Ph2P(CH2)2SPh-κP,κS)]PF6, (1)] was synthesized and characterized. Multinuclear (1H, 13C and 31P) NMR spectroscopy was employed for the determination of the structure. Moreover, SC-XRD confirmed the proposed structure belongs to the "piano stool" type. The Hirshfeld surface analysis outlined the most important intermolecular interactions in the structure. The crystallographic structure was optimized at the B3LYP-D3BJ/6-311++G(d,p)(H,C,P,S,Cl)/LanL2DZ(Ir) level of theory. The applicability of this level was verified through a comparison of experimental and theoretical bond lengths and angles, and 1H and 13C NMR chemical shifts. The Natural Bond Orbital theory was used to identify and quantify the intramolecular stabilization interactions, especially those between donor atoms and Ir(III) ions. Complex 1 was tested on antitumor activity against five human tumor cell lines: MCF-7 breast adenocarcinoma, SW480 colon adenocarcinoma, 518A2 melanoma, 8505C human thyroid carcinoma and A253 submandibular carcinoma. Complex 1 showed superior antitumor activity against cisplatin-resistant MCF-7, SW480 and 8505C cell lines. The mechanism of tumoricidal action on 8505C cells indicates the involvement of caspase-induced apoptosis, accompanied by a considerable reduction in ROS/RNS and proliferation potential of treated cells.

Abstract 4488: Newly developed organoiridium(III) complexes containing N,P-ligands possess antiproliferative activity in selected cancer cell lines

Abstract In conventional cancer treatment, platinum-based cytostatics are considered as standard therapy; however, they possess severe side effects. This fact leads to a constant effort to develop new non-platinum metallodrugs with different mechanism of action (MoA). In our study we developed new half-sandwich organoiridium(III) complexes, of general formulas [Ir(η5-Cp*)Cl(LNP)]PF6 (1-3) and [Ir(η5-Cpph)Cl(LNP)]PF6 (4-6) involving three different N,P-donor phosphinoalkylamines (LNP), which we tested on 2D and 3D cancer models; HCp* = pentamethylcyclopentadiene, HCpph= (2,3,4,5-tetramethylcyclopenta-2,4-dien-1-yl)benzene. The most effective complexes 3 and 6 bearing 3-(diphenylphosphanyl)propan-1-amine had the highest cytotoxic effect against various cancer cell lines (THP-1, HeLa, SW982, A549, MOR) including a cisplatin-resistant lung carcinoma cell line (MOR/CPR) with IC50 values between 3.1 and 9.1 μM for specific cell lines. The cytotoxic effect was further demonstrated on 3D spheroids of lung cancer cells that revealed anti-cancer and anti-migration potential of complexes 3 and 6. Cell cycle and cell death analysis showed a different mechanism compared to the effect of cisplatin. Moreover, complex 3 did not decrease cell viability of non-cancerous cells (peripheral blood mononuclear cells and porcine chondrocytes) under 50% at a concentration of 20 µM. In addition, we report for the first time that organoiridium complexes showed high cytotoxic activity on cancer cell lines, including cisplatin-resistant cell line, with different MoA from cisplatin. They trigger expression of stress-related genes associated with oxidative stress, DNA damage, and endoplasmic reticulum stress and, moreover, complex 3 showed cytotoxic selectivity towards cancer cells. This work was supported by the Czech health research council of the Ministry of Health of the Czech Republic (AZV Project NU22-08-00236). Citation Format: Renata Hezova, Jan Hosek, Nicol Strakova, Pavlina Simeckova, Josef Masek, Simona Kajabova, Pavel Starcha. Newly developed organoiridium(III) complexes containing N,P-ligands possess antiproliferative activity in selected cancer cell lines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4488.