Cisplatin-resistant Lung Cancer Research Articles

Transcriptome analysis reveals PRKCA as a potential therapeutic target for overcoming cisplatin resistance in lung cancer through ferroptosis

Cisplatin-based chemotherapy is the current standard care for lung cancer patients; however, drug resistance frequently develops during treatment, thereby limiting therapeutic efficacy.The molecular mechanisms underlying cisplatin resistance remain elusive. In this study, we conducted an analysis of microarray data from the Gene Expression Omnibus (GEO) database under the accession numbers GSE21656, which encompassed expression profiling of cisplatin-resistant H460 (DDP-H460)and the parental cells (H460). Subsequently, we calculated the differentially expressed genes (DEGs) between DDP-H460 and H460. Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of DEGs demonstrated significant impact on the Rap1, PI3K/AKT and MAPK signaling pathways. Moreover, protein and protein interaction (PPI) network analysis identified PRKCA, DET1, and UBE2N as hub genes that potentially contribute predominantly to cisplatin resistance. Ultimately, PRKCA was selected for validation due to its significant prognostic effect, which predicts unfavorable overall survival and disease-free survival in patients with lung cancer. Network analysis conducted on The Cancer Genome Atlas (TCGA) database revealed a strong gene-level correlation between PRKCA and TP53, CDKN2A, BYR2, TTN, KRAS, and PIK3CA; whereas at the protein level, it exhibited a high correlation with EGFR, Lck, Bcl2, and Syk. The in vitro experiments revealed that PRKCA was upregulated in the cisplatin-resistant A549 cells (DDP-A549), while knockdown of PRKCA increased DDP-A549 apoptosis upon cisplatin treatment. Moreover, we observed that PRKCA knockdown attenuated DDP-A549 proliferation, migration and invasion ability. Western blot analysis demonstrated that PRKCA knockdown downregulated phosphorylation of PI3K expression while upregulated the genes involved in ferroptosis signaling. In summary, our results elucidate the role of PRKCA in acquiring resistance to cisplatin and underscore its potential as a therapeutic target for cisplatin-resistant lung cancer.

Bithiophene-Functionalized Infrared Two-Photon Absorption Metal Complexes as Single-Molecule Platforms for Synergistic Photodynamic, Photothermal, and Chemotherapy.

A planar conjugated ligand functionalized with bithiophene and its Ru(II), Os(II), and Ir(III) complexes have been constructed as single-molecule platform for synergistic photodynamic, photothermal, and chemotherapy. The complexes have significant two-photon absorption at 808 nm and remarkable singlet oxygen and superoxide anion production in aqueous solution and cells when exposed to 808 nm infrared irradiation. The most potent Ru(II) complex Ru7 enters tumor cells via the rare macropinocytosis, locates in both nuclei and mitochondria, and regulates DNA-related chemotherapeutic mechanisms intranuclearly including DNA topoisomerase and RNA polymerase inhibition and their synergistic effects with photoactivated apoptosis, ferroptosis and DNA cleavage. Ru7 exhibits high efficacy in vivo for malignant melanoma and cisplatin-resistant non-small cell lung cancer tumors, with a 100% survival rate of mice, low toxicity to normal cells and low residual rate. Such an infrared two-photon activatable metal complex may contribute to a new generation of single-molecule-based integrated diagnosis and treatment platform to address drug resistance in clinical practice and phototherapy for large, deeply located solid tumors.

Folate-modified liposomes mediate the co-delivery of cisplatin with miR-219a-5p for the targeted treatment of cisplatin-resistant lung cancer

Cisplatin (DDP) resistance, often leading to first-line chemotherapy failure in non-small cell lung cancer (NSCLC), poses a significant challenge. MiR-219a-5p has been reported to enhance the sensitivity of human NSCLC to DDP. However, free miR-219a-5p is prone to degradation by nucleases in the bloodstream, rendering it unstable. In light of this, our study developed an efficient nanodrug delivery system that achieved targeted delivery of DDP and miR-219a-5p by modifying liposomes with folate (FA). Based on the results of material characterization, we successfully constructed a well-dispersed and uniformly sized (approximately 135.8 nm) Lipo@DDP@miR-219a-5p@FA nanodrug. Agarose gel electrophoresis experiments demonstrated that Lipo@DDP@miR-219a-5p@FA exhibited good stability in serum, effectively protecting miR-219a-5p from degradation. Immunofluorescence and flow cytometry experiments revealed that, due to FA modification, Lipo@DDP@miR-219a-5p@FA could specifically bind to FA receptors on the surface of tumor cells (A549), thus enhancing drug internalization efficiency. Safety evaluations conducted in vitro demonstrated that Lipo@DDP@miR-219a-5p@FA exhibited no significant toxicity to non-cancer cells (BEAS-2B) and displayed excellent blood compatibility. Cellular functional experiments, apoptosis assays, and western blot demonstrated that Lipo@DDP@miR-219a-5p@FA effectively reversed DDP resistance in A549 cells, inhibited cell proliferation and migration, and further promoted apoptosis. In summary, the Lipo@DDP@miR-219a-5p@FA nanodrug, through specific targeting of cancer cells and reducing their resistance to DDP, significantly enhanced the anti-NSCLC effects of DDP in vitro, providing a promising therapeutic option for the clinical treatment of NSCLC.

Role and mechanism of COL3A1 in regulating the growth, metastasis, and drug sensitivity in cisplatin-resistant non-small cell lung cancer cells

ABSTRACT Non-small cell lung cancer (NSCLC) is among the most difficult malignancies to treat. Type III collagen (COL3A1) can affect the progression and chemoresistance development of NSCLC. We herein explored the mechanism that drives COL3A1 dysregulation in NSCLC. Potential RNA-binding proteins (RBPs) and transcription factors (TFs) that could bind to COL3A1 were searched by bioinformatics. mRNA expression was detected by quantitative PCR. Protein expression was evaluated using immunoblotting and immunohistochemistry. The effects of the variables were assessed by gauging cell growth, invasiveness, migratory capacity, apoptosis, and cisplatin (DDP) sensitivity. The direct YY1/COL3A1 relationship was confirmed by ChIP and luciferase reporter experiments. Xenograft experiments were done to examine COL3A1’s function in DDP efficacy. COL3A1 showed enhanced expression in DDP-resistant NSCLC. In H460/DDP and A549/DDP cells, downregulation of COL3A1 exerted inhibitory functions in cell growth, invasiveness, and migration, as well as promoting effects on cell DDP sensitivity and apoptosis. Mechanistically, ELAV-like RNA binding protein 1 (ELAVL1) enhanced the mRNA stability and expression of COL3A1, and Yin Yang 1 (YY1) promoted the transcription and expression of COL3A1. Furthermore, upregulation of COL3A1 reversed ELAVL1 inhibition- or YY1 deficiency-mediated functions in DDP-resistant NSCLC cells. Additionally, COL3A1 downregulation enhanced the anti-tumor efficacy of DDP in vivo. Our investigation demonstrates that COL3A1 upregulation, induced by both RBP ELAVL1 and TF YY1, exerts important functions in phenotypes of NSCLC cells with DDP resistance, offering an innovative opportunity in the treatment of drug-resistant NSCLC.

Abstract 3065: Targeting of metabolic reprogramming in lung cancer by utilizing patient-derived organoid tissue for precision medicine

Abstract In a preliminary pilot study, we reported elevated activity of indoleamine 2,3-dioxygenase 1 (IDO1) in serum from cisplatin-resistant (CR) lung cancer patients compared to cisplatin-sensitive (CS) patients. This heightened IDO1 activity was associated with increased tryptophan (TRP) catabolism, resulting in the upregulation of kynurenine (KYN) production. The detection of KYN can now be readily achieved through immunohistochemistry (IHC). We demonstrated that this upregulation contributed to increased Treg (regulatory T cell) and MDSC (myeloid-derived suppressor cell) populations resulting in an immunosuppressive tumor microenvironment. To investigate this effect, we used dual inhibition of IDO1/TDO2 (tryptophan2,3-dioxygenase 2) in an orthotopic mouse model of CR-Lewis lung carcinoma. This resulted in a significant reduction in tumor volume compared to LLC-CS (n=7, p<0.01), confirming the role of TRP catabolism in CR tumorigenesis. To determine the relevance of the data derived from this mouse model to clinical settings, we established 50 patient-derived organoid tissues (PDOT) from patients with NSCLC. PDOT is an experimental ex vivo tissue model developed to recapitulate the intricate features of lung architecture, including the lung acinus. Upon optimizing our collection and growth protocols, each PDOT successfully developed into a spherical body within 14 days. Furthermore, through bulk RNA-seq analysis, we showed that PDOT closely mirrors the expression of key molecular markers (PD-L1 and mutations), as observed in the original tumor tissues. PDOT from patients possessing high levels of PD-L1 and KYN were exquisitely sensitive to dual inhibition with 2-3-fold greater sensitivity compared to patients with undetectable KYN expression in growth inhibition assays (GI50=20±5.5μM vs. 65±7.5μM). Increased lipid peroxidation was detected via flow cytometry by accumulation of the C11-BODIPY reporter dye in the dual inhibition treatment group. Moreover, we integrated PDOT with a novel 3D microfluidic culture that can be supplied with patient-matched peripheral blood mononuclear cells (PBMC) to assess immune response. Using CyTOF, we showed that dual inhibitors with Atezolizumab (anti-PD-L1) enhanced immune effector (CD8+, NK) and suppressed immunosuppressive (Treg, MDSC) populations. We believe that our swift progress in PDOT development may bridge the divide between cancer biomarker expression and patient trials by timely complementing conventional drug studies based on cell lines and xenografts to facilitate the design of personalized therapies. As a result, the extensive reporting that we have contributed for KYN expression profiling in CR has the potential to serve as a valuable companion diagnostic tool in the future. This can assist in applying precision oncology by finding the most appropriate patients for immunotherapies. Citation Format: Chunjing Wu, Jonathan D. Nguyen, George Theodore, Estelamari Rodriguez, Sydney Spector, Emily Kim, Taranatee Khan, Pablo Puente, Yujie Wang, Dao M. Nguyen, Cheng-Bang Chen, Diane Lim, Lynn G. Feun, Niramol Savaraj, Medhi Wangpaichitr. Targeting of metabolic reprogramming in lung cancer by utilizing patient-derived organoid tissue for precision medicine [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 3065.

Mitochondria-targeted neutral and cationic iridium(III) anticancer complexes chelating simple hybrid sp2-N/sp3-N donor ligands.

Most platinum group-based cyclometalated neutral and cationic anticancer complexes with the general formula [(C^N)2Ir(XY)]0/+ (neutral complex: XY = bidentate anionic ligand; cationic complex: XY = bidentate neutral ligand) are notable owing to their intrinsic luminescence properties, good cell permeability, interaction with some biomolecular targets and unique mechanisms of action (MoAs). We herein synthesized a series of neutral and cationic amine-imine cyclometalated iridium(III) complexes using Schiff base ligands with sp2-N/sp3-N N^NH2 chelating donors. The cyclometalated iridium(III) complexes were identified by various techniques. They were stable in aqueous media, displayed moderate fluorescence and exhibited affinity toward bovine serum albumin (BSA). The complexes demonstrated promising cytotoxicity against lung cancer A549 cells, cisplatin-resistant lung cancer A549/DDP cells, cervical carcinoma HeLa cells and human liver carcinoma HepG2 cells, with IC50 values ranging from 9.98 to 19.63 μM. Unfortunately, these complexes had a low selectivity (selectivity index: 1.62-1.98) towards A549 cells and BEAS-2B normal cells. The charge pattern of the metal center (neutral or cationic) and ligand substituents showed little influence on the cytotoxicity and selectivity of these complexes. The study revealed that these complexes could target mitochondria, cause depolarization of the mitochondrial membrane, and trigger the production of intracellular ROS. Additionally, the complexes were observed to induce late apoptosis and perturb the cell cycle in the G2/M or S phase in A549 cells. Based on these results, it appears that the anticancer efficacy of these complexes was predominantly attributed to the redox mechanism.

Polyphyllin II (PPII) Enhances the Sensitivity of Multidrug-resistant A549/DDP Cells to Cisplatin by Modulating Mitochondrial Energy Metabolism.

Cisplatin resistance often leads to treatment futility and elevated mortality rates in patients with lung cancer. One promising strategy to address this challenge involves the integration of traditional Chinese medicine (TCM) with chemotherapeutic drugs. Currently, the potential synergistic effect and underlying mechanism of polyphyllin II (PPII) and cisplatin combination in combating cisplatin (DDP) resistance in lung cancer remain unexplored. In this study, we established a cisplatin resistance model using A549 cells and explored the underlying mechanisms of PPII in combination with cisplatin in A549/DDP resistant cells. Specifically, we assessed the impact of PPII combined with cisplatin on A549/DDP cell proliferation, viability, and the expression of apoptosis-related proteins. To gain deeper insights into the underlying mechanism, we examined the effects of PPII and cisplatin on mitochondrial function in A549/DDP cells. This combination induced cell cycle arrest at both the S phase and G2/M phase in A549/DDP cells, thereby promoting apoptosis. Western blotting confirmed that DDP acted synergistically with PPII to enhance the expression of apoptotic proteins, diminish the expression of anti-apoptotic proteins, and promote the expression of anti-proliferation proteins in the mitochondrial pathway of A549/DDP cells. The combination of PPII and cisplatin effectively modulated the mitochondrial function, thereby reversing drug resistance in A549/DDP cells. This innovative combination therapy shows significant promise as a novel strategy for overcoming cisplatin resistance in lung cancer.

Z-Ligustilide Combined with Cisplatin Reduces PLPP1-Mediated Phospholipid Synthesis to Impair Cisplatin Resistance in Lung Cancer

Lung cancer is a malignant tumor with one of the highest morbidity and mortality rates in the world. Approximately 80–85% of lung cancer is diagnosed as non-small lung cancer (NSCLC), and its 5-year survival rate is only 21%. Cisplatin is a commonly used chemotherapy drug for the treatment of NSCLC. Its efficacy is often limited by the development of drug resistance after long-term treatment. Therefore, determining how to overcome cisplatin resistance, enhancing the sensitivity of cancer cells to cisplatin, and developing new therapeutic strategies are urgent clinical problems. Z-ligustilide is the main active ingredient of the Chinese medicine Angelica sinensis, and has anti-tumor activity. In the present study, we investigated the effect of the combination of Z-ligustilide and cisplatin (Z-ligustilide+cisplatin) on the resistance of cisplatin-resistant lung cancer cells and its mechanism of action. We found that Z-ligustilide+cisplatin decreased the cell viability, induced cell cycle arrest, and promoted the cell apoptosis of cisplatin-resistant lung cancer cells. Metabolomics combined with transcriptomics revealed that Z-ligustilide+cisplatin inhibited phospholipid synthesis by upregulating the expression of phospholipid phosphatase 1 (PLPP1). A further study showed that PLPP1 expression was positively correlated with good prognosis, whereas the knockdown of PLPP1 abolished the effects of Z-ligustilide+cisplatin on cell cycle and apoptosis. Specifically, Z-ligustilide+cisplatin inhibited the activation of protein kinase B (AKT) by reducing the levels of phosphatidylinositol 3,4,5-trisphosphate (PIP3). Z-ligustilide+cisplatin induced cell cycle arrest and promoted the cell apoptosis of cisplatin-resistant lung cancer cells by inhibiting PLPP1-mediated phospholipid synthesis. Our findings demonstrate that the combination of Z-Ligustilide and cisplatin is a promising approach to the chemotherapy of malignant tumors that are resistant to cisplatin.

Novel Platinum(IV) complexes intervene oxaliplatin resistance in colon cancer via inducing ferroptosis and apoptosis

Platinum-based chemotherapeutics are widely used for cancer treatment but are frequently limited because of dosage-dependent side effects and drug resistance. To attenuate these drawbacks, a series of novel platinum(IV) prodrugs (15a–18c) were synthesized and evaluated for anti-cancer activity. Among them, 17a demonstrated superior anti-proliferative activity compared with oxaliplatin (OXA) in the cisplatin-resistant lung cancer cell line A549/CDDP and OXA-resistant colon cancer cell line HCT-116/OXA but showed a lower cytotoxic effect toward human normal cell lines HUVEC and L02. Mechanistic investigations suggested that 17a efficiently enhanced intracellular platinum accumulation, induced DNA damage, disturbed the homeostasis of intracellular reactive oxygen molecules and mitochondrial membrane potential, and thereby activated the mitochondrion-dependent apoptosis pathway. Moreover, 17a significantly induced ferroptosis in HCT-116/OXA via triggering the accumulation of lipid peroxides, disrupting iron homeostasis, and inhibiting solute carrier family 7 member 11 and glutathione peroxidase 4 axial pathway transduction by inhibiting the expression of the phosphorylated signal transducer and activator of transcription 3 and nuclear factor erythroid 2‐related factor 2. Moreover, 17a exerted remarkable in vivo antitumor efficacy in the HCT-116/OXA xenograft models but showed attenuated toxicity. These results indicated that these novel platinum(IV) complexes provided an alternative strategy to develop novel platinum-based antineoplastic agents for cancer treatment.

NAD (P)H Quinone Dehydrogenase 1-Targeting Triptolide Analogue Causes Tumor Regression and Sensitizes Cisplatin-Resistant Lung Cancer to Chemotherapy.

Cisplatin (DDP) is a first-line chemotherapeutic drug against lung cancer. Nonetheless, the effectiveness of this drug is hampered by drug resistance. Overcoming drug resistance is crucial for improving the outcomes of lung cancer treatment. Here, we reported the effect of CX-23, an activated triptolide analogue that targets NAD (P)H quinone dehydrogenase 1 (NQO1), on DDP-resistant lung cancer and sensitizes DDP-resistant lung cancer to chemotherapy. Our findings unveiled the antiproliferative activity of CX-23 against both A549- and DDP-resistant A549 (A549/DDP) cells while enhancing the chemosensitivity of these cells to DDP. Notably, CX-23 demonstrated no toxicity toward normal lung cells. Further investigations revealed that CX-23 exerts its effects by blocking AKT phosphorylation, leading to reduced expression of Mcl-1 and Bcl-2, and upregulating cleaved-caspase-3 levels, ultimately inducing apoptosis in cancer cells. CX-23 can be rapidly transformed in both A549 and A549/DDP cell lysates while remaining stable in mouse plasma and normal lung tissues. Pharmacokinetic analysis showed that CX-23 can distribute to lung tissues. Moreover, in vivo studies showed that CX-23 can prevent DDP-resistant lung cancer progression without causing any toxicity in the liver, kidneys, or lungs after 6 weeks of treatment. The combination of CX-23 and DDP not only significantly inhibited tumor progression compared to DDP alone but also attenuated DDP-induced kidney toxicity. These findings suggest that CX-23 alone or in combination with DDP may provide an alternative therapeutic option for DDP-resistant lung cancer.

Andrographis modulates cisplatin resistance in lung cancer via miR-155-5p/SIRT1 axis.

Andrographis (Andro) has been identified as an anti-cancer herbal. This study was to explore its underlying regulatory routes regarding cisplatin (DDP) resistance in lung cancer. The impacts of Andro on cell viability in lung cancer cells and normal cells BEAS-2B were validated using CCK8 tests. Then, cell viability and apoptosis analysis was performed in the cells after DDP, Andro, or combined treatment. RT-qPCR was applied for evaluating miR-155-5p and SIRT1 mRNA expressions, while western blot was for evaluating SIRT1 protein expressions. Binding sites between SIRT1 and miR-155-5p were predicted on TargetScan and were confirmed using luciferase reporter assays. Xenograft animal models were established for in vivo validation of the regulatory function of Andro in lung cancer. Andro decreased the cell viability in lung cancer cells but not normal cells BEAS-2B. The combined treatment with DDP and Andro induced the lowest viability and highest apoptosis in both A549 and A549/DDP cells. MiR-155-5p expression was suppressed, and SIRT was promoted by the Andro treatment, while overexpression of miR-155-5p reversed effects of Andro in cells, which was further counteracted by SIRT1 activation. SIRT1 was verified to be a target of miR-155-5p in A549/DDP cells. Moreover, Andro synergized with DDP in mice with lung cancer via miR-155-5p/SIRT1. Andro modulates cisplatin resistance in lung cancer via miR-155-5p/SIRT1 axis.

Integrative analysis illustrates the role of PCDH7 in lung cancer development, cisplatin resistance, and immunotherapy resistance: an underlying target.

Background: Cisplatin resistance is a common clinical problem in lung cancer. However, the underlying mechanisms have not yet been fully elucidated, highlighting the importance of searching for biological targets. Methods: Bioinformatics analysis is completed through downloaded public data (GSE21656, GSE108214, and TCGA) and specific R packages. The evaluation of cell proliferation ability is completed through CCK8 assay, colony formation, and EdU assay. The evaluation of cell invasion and migration ability is completed through transwell and wound-healing assays. In addition, we evaluated cell cisplatin sensitivity by calculating IC50. Results: Here, we found that PCDH7 may be involved in cisplatin resistance in lung cancer through public database analysis (GSE21656 and GSE108214). Then, a series of in vitro experiments was performed, which verified the cancer-promoting role of PCDH7 in NSCLC. Moreover, the results of IC50 detection showed that PCDH7 might be associated with cisplatin resistance of NSCLC. Next, we investigated the single-cell pattern, biological function, and immune analysis of PCDH7. Importantly, we noticed PCDH7 may regulate epithelial-mesenchymal transition activity, and the local infiltration of CD8+ T and activated NK cells. Furthermore, we noticed that patients with high PCDH7 expression might be more sensitive to bortezomib, docetaxel, and gemcitabine, and resistant to immunotherapy. Finally, a prognosis model based on three PCDH7-derived genes (GPX8, BCAR3, and TNS4) was constructed through a machine learning algorithm, which has good prediction ability on NSCLC patients' survival. Conclusion: Our research has improved the regulatory framework for cisplatin resistance in NSCLC and can provide direction for subsequent related research, especially regarding PCDH7.

Circ_0010235 confers cisplatin resistance in lung cancer by upregulating E2F7 through absorbing miR-379-5p.

Cisplatin (DDP) treatment is one of the most predominant chemotherapeutic strategies for lung cancer patients. Circular RNAs (circRNAs) have been revealed to participate in the chemoresistance in lung cancer. Hence, the role and mechanism of circ_0010235 in cisplatin resistance in lung cancer was investigated. Expression levels of circ_0010235, microRNA (miR)-379-5p and E2F transcription factor 7 (E2F7) were analyzed using quantitative reverse transcription PCR (qRT-PCR) and western blot. Cell DDP sensitivity, proliferation, apoptosis, invasion, and migration were detected by cell counting kit-8 assay, 5-ethynyl-2'-deoxyuridine (EDU) assay, flow cytometry and western blot, respectively. The binding interaction was verified using dual-luciferase reporter assay. A murine xenograft model was established to investigate effects in vivo. Circ_0010235 was highly expressed in DDP-resistant lung cancer tissues and cells. Knockdown of circ_0010235 elevated DDP sensitivity, constrained proliferation, invasion and migration as well as fostered apoptosis in DDP-resistant lung cancer cells. Moreover, circ_0010235 silencing boosted DDP sensitivity and impeded tumor growth in lung cancer in vivo. Mechanistically, circ_0010235 acted as a sponge for miR-379-5p to elevate the expression of its target E2F7. Rescue experiments showed that miR-379-5p inhibition attenuated circ_0010235 knockdown-evoked reduction on DDP resistance of DDP-resistant cancer cells. In addition, miR-379-5p re-expression elevated DDP sensitivity and suppressed the malignant phenotype of DDP-resistant lung cancer cells through miR-379-5p. Circ_0010235 knockdown reduced DDP resistance and tumor growth via miR-379-5p/ E2F7 axis in lung cancer, suggesting an effective therapeutic target for lung cancer patients.

Inhibitory Effect and Mechanism of Ursolic Acid on Cisplatin-Induced Resistance and Stemness in Human Lung Cancer A549 Cells.

The survival rate of lung cancer patients remains low largely due to chemotherapy resistance during treatment, and cancer stem cells (CSCs) may hold the key to targeting this resistance. Cisplatin is a chemotherapy drug commonly used in cancer treatment, yet the mechanisms of intrinsic cisplatin resistance have not yet been determined because lung CSCs are hard to identify. In this paper, we proposed a mechanism relating to the function of ursolic acid (UA), a new drug, in reversing the cisplatin resistance of lung cancer cells regulated by CSCs. Human lung cancer cell line A549 was selected as the model cell and treated to become a cisplatin-resistant lung cancer cell line (A549-CisR), which was less sensitive to cisplatin and showed an enhanced capability of tumor sphere formation. Furthermore, in the A549-CisR cell line expression, levels of pluripotent stem cell transcription factors Oct-4, Sox-2, and c-Myc were increased, and activation of the Jak2/Stat3 signaling pathway was promoted. When UA was applied to the cisplatin-resistant cells, levels of the pluripotent stem cell transcription factors were restrained by the inhibition of the Jak2/Stat3 signaling pathway, which reduced the enrichment of tumor stem cells, and in turn, reversed cisplatin resistance in lung cancer cells. Hence, as a potential antitumor drug, UA may be able to inhibit the enrichment of the lung CSC population by inhibiting the activation of the Jak2-Stat3 pathway and preventing the resistance of lung cancer cells to cisplatin.

Abstract 3903: Role of the miR-301a/Fra-2/GLIPR1 axis in lung cancer cisplatin resistance

Abstract Lung cancer is the leading cause of cancer-related mortality in both men and women worldwide. Despite the administration of platinum compounds represents the main treatment, the majority of tumors remains intrinsically resistant. In lung cancer, miR-301a exerts a main role by modulating the activity of transcription factors like NF-kB and Stat3. Here, we dissected the contribution of miR-301a in the regulation of its new identified target Fos-related antigen-2 (Fra-2), a transcription factor that belongs to the Fos/AP-1 family. By microarray analysis, we discovered that Fra-2 overexpression increased glioma pathogenesis-related protein 1 (GLIPR1) levels, a mediator of cisplatin resistance in lung cancer. Its mechanism of regulation is still unclear. We demonstrated that GLIPR1 is also a miR-301a target. In vitro, modulation of miR-301a reduced Fra-2 and GLIPR1 levels; conversely, Fra-2 overexpression significantly increased GLIPR1 and miR-301a. Then, by chromatin immunoprecipitation assay, we confirmed that Fra-2 interacts with the promoter regions of both GLIPR1 and MIR301A genes, supporting that miR-301a/Fra-2/GLIPR1 axis could be autoregulated by feedback loop in which Fra-2 promotes the transcription of MIR301A gene. Investigating the effect of this new axis on the response to cisplatin, we observed that both Fra-2/GLIPR1 overexpression and miR-301a silencing induced cisplatin resistance in lung cancer cells. By contrast, silencing of GLIPR1 and combined administration of low doses of Fos/AP-1 inhibitor restored the cisplatin sensitivity in Fra-2 overexpressing cells. In the lung adenocarcinoma samples from the TCGA dataset, miR-301a overexpression inversely correlated with Fra-2 and GLIPR1 expression. Consistently, the overexpression of miR-301a identified a fraction of tumors with low expression of Fra-2 and GLIPR1 in an internal cohort of lung cancer samples. Altogether, our findings identify the miR-301a/Fra-2/GLIPR1 axis that contributes to cisplatin resistance in lung cancer cells and could serve as biomarker to stratify patients who may benefit from cisplatin administration, alone or in combination with Fos/AP-1 inhibitors. Citation Format: Francesca Lovat, Gian Luca Rampioni Vinciguerra, Marina Capece, Rosario Distefano, Giovanni Nigita, Andrea Vecchione, Carlo M. Croce. Role of the miR-301a/Fra-2/GLIPR1 axis in lung cancer cisplatin resistance. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3903.

Targeting Rab26 to Conquer Cisplatin-Resistant Lung Cancer with Self-Assembled DNA Nanomaterials

Overcoming cisplatin-based drug resistance in lung cancer remains an enormous challenge in clinical tumor therapy worldwide. Recent studies have reported that some Rab GTPases are involved in multiple aspects of tumor progression, including invasion, migration, metabolism, autophagy, exosome secretion, and drug resistance. In particular, Rab26 is essential to vital processes such as vesicle-mediated secretion, cell growth, apoptosis, and autophagy. In this study, we developed a nanosystem based on programmed DNA self-assembly of Rab26 siRNA-loaded nanoparticles (siRNP). We demonstrated that siRNP could be effectively transfected into cisplatin-resistant A549 (A549/DDP) cells. These siRab26-carrying nanoparticles induced apoptosis and inhibited the disruption of autophagy. The combination therapy of siRab26 knockdown with cisplatin could improve the antitumor therapy compared with a single one in vitro. In nude mice, siRNP enhanced the chemosensitivity of cisplatin-resistant cells and inhibited tumor xenograft development. These outcomes suggest that siRNP is an effective platform for lung cancer therapy in cases exhibiting drug resistance.

Targeted therapy for cisplatin-resistant lung cancer via aptamer-guided nano-zinc carriers containing USP14 siRNA.

Cisplatin (DDP) is a common therapeutic option for non-small cell lung carcinoma (NSCLC). However, some patients fail to respond to the DDP chemotherapy. Therefore, identifying novel biomarkers to improve the diagnosis and treatment of NSCLC is important. Ubiquitin-specific protease (USP14) is involved in various pathological conditions including cancer; however, the role of USP14 in NSCLC remains elusive. The SELEX technology was used to identify aptamers that specifically recognize DDP-resistant lung cancer cells and couple them with nano-zinc (zinc hydroxide, Zn(OH)2) carriers. USP14 levels were higher in DDP-resistant lung cancer compared to DDP-sensitive lung cancer. The survival rate of lung cancer patients with increased USP14 expression was significantly lower than the survival rate of patients with low USP14 expression. Silencing USP14 increased the tumor antagonistic action of DDP in A549 cisplatin-resistant (A549/DDP) cells, while USP14 overexpression decreased the antagonist effects. Aptamer-targeted nano-zinc carriers were loaded with USP14 siRNA to target DDP-resistant lung cancer cells. Aptamer-targeted nano-zinc carriers containing USP14 siRNA increased the antitumor effects of DDP in A549/DDP cells and mice bearing A549/DDP cells. These results indicate that aptamer-guided nano-zinc carriers may be a potent carrier for the precise treatment of drug-resistant tumors.

New Guaiane-Type Sesquiterpenoids Biscogniauxiaols A-G with Anti-Fungal and Anti-Inflammatory Activities from the Endophytic Fungus Biscogniauxia Petrensis.

Seven undescribed guaiane-type sesquiterpenoids named biscogniauxiaols A-G (1-7) were isolated from the endophytic fungus Biscogniauxia petrensis on Dendrobium orchids. Their structures were determined by extensive spectroscopic analyses, electronic circular dichroism (EC) and specific rotation (SR) calculations. Compound 1 represented a new family of guaiane-type sesquiterpenoids featuring an unprecedented [5/6/6/7] tetracyclic system. A plausible biosynthetic pathway for compounds 1-7 was proposed. The anti-fungal, anti-inflammatory and multidrug resistance reversal activities of the isolates were evaluated. Compounds 1, 2 and 7 exhibited potent inhibitory activities against Candida albicans with MIC values ranging from 1.60 to 6.30 μM, and suppressed nitric oxide (NO) production with IC50 ranging from 4.60 to 20.00 μM. Additionally, all compounds (100 μg/mL) enhanced the cytotoxicity of cisplatin in cisplatin-resistant non-small cell lung cancer cells (A549/DDP). This study opened up a new source for obtaining bioactive guaiane-type sesquiterpenoids and compounds 1, 2, and 7 were promising for further optimization as multifunctional inhibitors for anti-fungal (C. albicans) and anti-inflammatory purposes.

Novel Indole-Chalcone Derivative-Ligated Platinum(IV) Prodrugs Attenuate Cisplatin Resistance in Lung Cancer through ROS/ER Stress and Mitochondrial Dysfunction.

Developing multifunctional platinum(IV) prodrugs via integrating bioactive pharmacophores into one entity is an attractive strategy to ameliorate the defects of platinum(II) drugs. Herein, a series of indole-chalcone derivative-ligated platinum(IV) complexes were synthesized and evaluated for their anticancer activities. Among them, optimal complex 17a exerted superior activity compared to that of cisplatin (CDDP) against the tested cells but showed lower cytotoxicity toward human normal lung cells. Detailed mechanisms demonstrated that 17a significantly enhanced intracellular accumulation, induced DNA damage, and inhibited migration in A549/CDDP cells. Furthermore, 17a efficiently disturbed the tubulin-microtubule system, initiated reactive oxygen species (ROS)-mediated endoplasmic reticulum stress, and activated a mitochondrion-dependent apoptosis signaling pathway. Besides, 17a was superior to free drugs or their combination in inhibiting cancer growth in A549/CDDP xenografts without inducing obvious side effects. The physical mixture of 16a and CDDP was almost identical to 17a but showed apparent systematic side effects. In summary, our studies may provide an efficient treatment regimen for CDDP resistance.

Targeting Mitochondrial IDH2 Enhances Antitumor Activity of Cisplatin in Lung Cancer via ROS-Mediated Mechanism

Mitochondrial isocitrate dehydrogenase 2 (IDH2) is an important metabolic enzyme in the tricarboxylic acid cycle (TCA) cycle. Our previous study showed that high expression of wild-type IDH2 promotes the proliferation of lung cancer cells. This study aims to test the potential of targeting IDH2 as a therapeutic strategy to inhibit lung cancer in vitro and in vivo. First, we analyzed the available data from the databases gene expression omnibus (GEO) database to evaluate the clinical relevance of IDH2 expression in affecting lung cancer patient survival. We then generated a stable IDH2-knockdown lung cancer cell line using a lentivirus-based method for in vitro and in vivo study. Cell growth, apoptosis, cell viability, and colony formation assays were conducted to test the sensitivity of lung cancer cells with different IDH2 expression status to cisplatin or radiation treatment in vitro. For mechanistic study, Cellular oxygen consumption and extracellular acidification rates were measured using a Seahorse metabolic analyzer, and reactive oxygen species (ROS) generation was analyzed using flow cytometry. An animal study using a xenograft tumor model was performed to further evaluate the in vivo therapeutic effect on tumor growth. We found that high IDH2 expression was associated with poor survival in lung cancer patients undergoing chemotherapy. Inhibition of IDH2 significantly enhanced the anticancer activity of cisplatin and also increased the effect of radiation against lung cancer cells. IDH2 was upregulated in cisplatin-resistant lung cancer cells, which could be sensitized by targeted inhibition of IDH2. Mechanistic study showed that abrogation of IDH2 caused only minimal changes in oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) in lung cancer cells, but induced a significant increase in ROS, which rendered the cancer cells more sensitive to cisplatin. Pretreatment of lung cancer cells with the ROS scavenger N-acetyl-cysteine could partially rescue cells from the cytotoxic effect of cisplatin and IDH2 inhibition. Importantly, abrogation of IDH2 significantly increased the sensitivity of lung cancer cells to cisplatin in vivo.