Cisplatin-resistant Non-small Cell Lung Cancer Research Articles

P32/OPA1 axis-mediated mitochondrial dynamics contributes to cisplatin resistance in non-small cell lung cancer.

Cisplatin resistance is a major obstacle in the treatment of non-small cell lung cancer (NSCLC). p32 and OPA1 are the key regulators of mitochondrial morphology and function. This study aims to investigate the role of the p32/OPA1 axis in cisplatin resistance in NSCLC and its underlying mechanism. The levels of p32 protein and mitochondrial fusion protein OPA1 are higher in cisplatin-resistant A549/DDP cells than in cisplatin-sensitive A549 cells, which facilitates mitochondrial fusion in A549/DDP cells. In addition, the expression of p32 and OPA1 protein is also upregulated in A549 cells during the development of cisplatin resistance. Moreover, p32 knockdown effectively downregulates the expression of OPA1, stimulates mitochondrial fission, decreases ATP generation and sensitizes A549/DDP cells to cisplatin-induced apoptosis. Furthermore, metformin significantly downregulates the expressions of p32 and OPA1 and induces mitochondrial fission and a decrease in ATP level in A549/DDP cells. The co-administration of metformin and cisplatin shows a significantly greater decrease in A549/DDP cell viability than cisplatin treatment alone. Moreover, D-erythro-Sphingosine, a potent p32 kinase activator, counteracts the metformin-induced downregulation of OPA1 and mitochondrial fission in A549/DDP cells. Taken together, these findings indicate that p32/OPA1 axis-mediated mitochondrial dynamics contributes to the acquired cisplatin resistance in NSCLC and that metformin resensitizes NSCLC to cisplatin, suggesting that targeting p32 and mitochondrial dynamics is an effective strategy for the prevention of cisplatin resistance.

β-elemene enhances cisplatin sensitivity of non-small cell lung cancer cells via the miR-17-5p/STAT3 axis.

In China, β-elemene, a sesquiterpene compound derived from Curcuma wenyujin, is clinically used to treat many human malignancies, including non-small cell lung cancer (NSCLC). Nonetheless, the role of β-elemene in regulating cisplatin sensitivity of NSCLC cells and the related mechanisms are not clear. This study was conducted to investigate the role of β-elemene in sensitizing NSCLC cells to cisplatin. In this work, cisplatin-resistant NSCLC cell lines were constructed. CCK-8, colony formation, and flow cytometry assays were executed to examine cell viability, growth, and apoptosis. MiR-17-5p and STAT3 expression levels in cells were detected by qRT-PCR. Western blot was executed to determine the expression levels of STAT3 and apoptosis-related proteins (Bax and Bcl-2) in the cells. Dual-luciferase reporter gene experiments were performed to verify the targeting relationship between miR-17-5p and STAT3. Herein, we report that, β-elemene inhibits the viability, and induces the apoptosis of cisplatin-resistant NSCLC cells. Additionally, β-elemene induces the upregulation miR-17-5p and downregulation of STAT3. STAT3 is validated to be a target of miR-17-5p in NSCLC cells. Additionally, the role of β-elemene to repress the viability of cisplatin-resistant NSCLC cells is partially counteracted by miR-17-5p inhibitor or STAT3 overexpression. In summary, our study suggests that β-elemene enhances cisplatin sensitivity of NSCLC cells by modulating miR-17-5p/STAT3 axis, and it may be a choice for the complementary treatment of NSCLC patients.

Mechanism of PWAR6 regulating cisplatin drug sensitivity in non-small cell lung cancer through miR-577/PHACTR1

lncRNA Prader Willi/Angelman Region RNA 6 (PWAR6) is considered to play a protective lncRNA in glioma, but, the role of PWAR6 in the occurrence and cisplatin resistance of non-small cell lung cancer (NSCLC) is elusive. In the study, we aimed to assess the role of PWAR6 in the cisplatin resistance of NSCLC. Based on the oebiotech and TargetScanHuman database, we predicted the interaction between PWAR6, miR-577 and PHACTR1. We then used small interfering RNA (siRNA), miRNA mimics and dual-luciferase reporter assay to explore the regulatory role of PWAR6/miR-577PHACTR1. Based on the online database, miR-577 can interact with PWAR6 and PHACTR1. Soon afterwards, we observed that the expression of PWAR6 and PHACTR1 was increased, while miR-577 expression was decreased in A549/DDP cells. And the cell viability was decreased, while cell apoptosis was increased in A549/DDP cells. What’s more, PWAR6 knockdown can promote the expression of miR-577 and inhibit the expression of PHACTR1. PWAR6 knockdown elevated cell proliferation and reduced cell apoptosis of A549/DDP cells. Interestingly, we found that miR-577 can interact with PHACTR1 to regulate the proliferation and apoptosis of A549/DDP cells. To conclude, we speculated that PWAR6 knockdown elevated cell proliferation and reduced cell apoptosis of A549/DDP cells via miR-577/PHACTR1, providing the theoretical basis for the clinical treatment of NSCLC patients.

Cisplatin-activated ERβ/DCAF8 positive feedback loop induces chemoresistance in non-small cell lung cancer via PTEN/Akt axis

High levels of the estrogen receptor β (ERβ) predict poor prognosis following platinum-containing adjuvant chemotherapies in patients with non-small cell lung cancer (NSCLC). However, the precise role of ERβ remains elusive. In this study, we demonstrated that targeting ERβ could significantly increase the cytotoxicity of cisplatin both in vitro and in vivo. Mechanically, cisplatin directly binds to ERβ, which facilitates its homodimerization and nuclear translocation. ERβ activation transcriptionally represses the expression of DCAF8, an adaptor of CRL4 E3 ubiquitin ligase, which in turn attenuates the proteasomal degradation of ERβ, leading to ERβ accumulation; this positive feedback loop results in Akt activation and eventually cisplatin resistance in NSCLC through PTEN inhibition. Moreover, low expression of DCAF8 and high expression of ERβ are associated with treatment resistance in patients receiving cisplatin-containing adjuvant chemotherapy. The present results provide insights into the underlying mechanism of ERβ-induced cisplatin resistance and offer an alternative therapeutic strategy to improve the efficacy of platinum-based chemotherapy in patients with NSCLC.

A dynamic Boolean network reveals that the BMI1 and MALAT1 axis is associated with drug resistance by limiting miR-145-5p in non-small cell lung cancer

Patients with non-small cell lung cancer (NSCLC) are often treated with chemotherapy. Poor clinical response and the onset of chemoresistance limit the anti-tumor benefits of drugs such as cisplatin. According to recent research, metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a long non-coding RNA related to cisplatin resistance in NSCLC. Furthermore, MALAT1 targets microRNA-145-5p (miR-145), which activates Krüppel-like factor 4 (KLF4) in associated cell lines. B lymphoma Mo-MLV insertion region 1 homolog (BMI1), on the other hand, inhibits miR-145 expression, which stimulates Specificity protein 1 (Sp1) to trigger the epithelial–mesenchymal transition (EMT) process in pemetrexed-resistant NSCLC cells. The interplay between these molecules in drug resistance is still unclear. Therefore, we propose a dynamic Boolean network that can encapsulate the complexity of these drug-resistant molecules. Using published clinical data for gain or loss-of-function perturbations, our network demonstrates reasonable agreement with experimental observations. We identify four new positive circuits: miR-145/Sp1/MALAT1, BMI1/miR-145/Myc, KLF4/p53/miR-145, and miR-145/Wip1/p38MAPK/p53. Notably, miR-145 emerges as a central player in these regulatory circuits, underscoring its pivotal role in NSCLC drug resistance. Our circuit perturbation analysis further emphasizes the critical involvement of these new circuits in drug resistance for NSCLC. In conclusion, targeting MALAT1 and BMI1 holds promise for overcoming drug resistance, while activating miR-145 represents a potential strategy to significantly reduce drug resistance in NSCLC.

Huaier suppresses cisplatin resistance in non-small cell lung cancer by inhibiting the JNK/JUN/IL-8 signaling pathway

Ethnopharmacological relevanceHuaier (Trametes robiniophila Murr), a traditional Chinese medicinal fungus, possesses potent anticancer efficacy and has been used as an adjuvant medication for liver, breast, gastric, intestinal, and non-small cell lung cancer (NSCLC). However, the potential regulatory functions and underlying molecular mechanisms of Huaier in cisplatin resistance of NSCLC remain unknown. AimTo evaluate the potential regulatory functions and underlying molecular mechanisms of Huaier in cisplatin resistance of NSCLC. Materials and methodsIn vitro and in vivo experiments were employed to evaluate the regulatory functions of Huaier in cisplatin-resistant NSCLC cells. Transcriptome sequencing and validation analyses was undertaken to identify the downstream targets of Huaier. Network pharmacology, ultra-performance liquid chromatography-mass spectroscopy, and in vitro and in vivo experiments were performed to identify key small molecule drug candidates in Huaier and the regulatory mechanisms these employ to suppress cisplatin resistance in NSCLC. ResultsHuaier suppressed cisplatin resistance and cancer cell stemness in cisplatin-resistant NSCLC cells, both in vitro and in vivo. Mechanistically, Huaier could suppress expression of interleuken-8 (IL-8) through inhibition of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and activator protein-1 (AP-1), two key transcription factors responsible for the activation of IL-8 transcription. Kaempferol was identified as one of the key small molecule compounds in Huaier that could suppress cisplatin resistance by inhibiting the phosphorylation and nuclear translocation of proto-oncogene c-Jun (JUN) by binding and inhibiting the kinase activity of c-Jun N-terminal protein kinase (JNK). ConclusionsHuaier suppressed cisplatin resistance of NSCLC cells by inhibiting the JNK/JUN/IL-8 signaling pathway.

Prominin 2 decreases cisplatin sensitivity in non-small cell lung cancer and is modulated by CTCC binding factor.

Non-small cell lung cancer (NSCLC) is the major pathological type of lung cancer and accounts for the majority of lung cancer-related deaths worldwide. We investigated the molecular mechanism of prominin 2 (PROM2) involved in cisplatin resistance in NSCLC. The GEO database was analyzed to obtain differential genes to target PROM2. Immunohistochemistry and western blotting were used to detect protein expression levels. To examine the role of PROM2 in NSCLC, we overexpressed or knocked down PROM2 by transfection of plasmid or small interfering RNA. In functional experiments, CCK8 was used to detect cell viability. Cell migration and invasion and apoptosis were detected by transwell assay and flow cytometry, respectively. Mechanistically, the regulation of PROM2 by CTCF was detected by ChIP-PCR. In vivo experiments confirmed the role of PROM2 in NSCLC. GEO data analysis revealed that PROM2 was up-regulated in NSCLC, but its role in NSCLC remains unclear. Our clinical samples confirmed that the expression of PROM2 was markedly increased in NSCLC tissue. Functionally, Overexpression of PROM2 promotes cell proliferation, migration and invasion, and cisplatin resistance. CTCF up-regulates PROM2 expression by binding to its promoter region. In vivo experiments confirmed that PROM2 knockdown could inhibit tumor growth and increase the sensitivity of tumor cells to cisplatin. PROM2 up-regulation in NSCLC can attenuate the sensitivity of NSCLC cells to cisplatin and promote the proliferation, migration and invasion of tumor cells. PROM2 may provide a new target for the treatment of NSCLC.

Skp2-mediated MLKL degradation confers cisplatin-resistant in non-small cell lung cancer cells

Non-small cell lung cancer (NSCLC) is the most prevalent type of cancer and the leading cause of cancer-related death. Chemotherapeutic resistance is a major obstacle in treating NSCLC patients. Here, we discovered that the E3 ligase Skp2 is overexpressed, accompanied by the downregulation of necroptosis-related regulator MLKL in human NSCLC tissues and cell lines. Knockdown of Skp2 inhibited viability, anchorage-independent growth, and in vivo tumor development of NSCLC cells. We also found that the Skp2 protein is negatively correlated with MLKL in NSCLC tissues. Moreover, Skp2 is increased and accompanied by an upregulation of MLKL ubiquitination and degradation in cisplatin-resistant NSCLC cells. Accordingly, inhibition of Skp2 partially restores MLKL and sensitizes NSCLC cells to cisplatin in vitro and in vivo. Mechanistically, Skp2 interacts and promotes ubiquitination-mediated degradation of MLKL in cisplatin-resistant NSCLC cells. Our results provide evidence of an Skp2-dependent mechanism regulating MLKL degradation and cisplatin resistance, suggesting that targeting Skp2-ubiquitinated MLKL degradation may overcome NSCLC chemoresistance.

Elevated HMGB1 promotes the malignant progression and contributes to cisplatin resistance of non-small cell lung cancer

BackgroundHMGB1 (high mobility group box B-1) exhibits crucial role in tumor genesis and development, including lung cancer. Whereas, more HMGB1-related details in non-small cell lung cancer (NSCLC) are still largely unclear.MethodsThe HMGB1 and inflammatory factors in malignant (MPE) and non-malignant pleural effusion (BPE) were determined by ELISA. Additionally, qRT-PCR, western blot, or immunohistochemistry were used to determine HMGB1, drug-resistant and apoptotic proteins’ expressions in NSCLC A549, A549-DDP cell lines, and xenograft model. Cell viability, migration/ invasion, and apoptosis were analyzed using MTT, Transwell, and flow cytometry assays, respectively.ResultsInflammatory factors and HMGB1 expressions in MPE were significantly higher than BPE of NSCLC. Compared with preoperative and adjacent tissues, significantly higher HMGB1, drug-resistant protein, and anti-apoptotic protein expressions were observed in recurrent tissues. Overexpressed HMGB1 induced NSCLC cells to exhibit stronger aggressive, proliferative, and drug-resistant features. The related abilities were reversed when HMGB1 was interfered. Overexpressed HMGB1 showed a similar co-localization with drug resistant protein P-gp in cytoplasm in xenograft model, while low HMGB1 expression localized in cell nucleus.ConclusionsHMGB1 overexpression significantly promoted the malignant progression and cisplatin resistance of NSCLC in vitro and in vivo.

LncRNA ITGB2-AS1 promotes cisplatin resistance of non-small cell lung cancer by inhibiting ferroptosis via activating the FOSL2/NAMPT axis

ABSTRACT Cisplatin resistance is a major therapeutic challenge in non-small cell lung cancer (NSCLC). Herein, the regulatory role of long non-coding RNA (lncRNA) ITGB2-AS1 in regulating NSCLC cisplatin resistance was investigated. NSCLC cisplatin resistance cells were constructed using A549 and H1975 cells. Cell viability and proliferation were detected by MTT assay and colony formation assay, respectively. Cell apoptosis and cell cycle were examined by flow cytometry. GSH, MDA, ROS, and Fe2+ levels were measured by the corresponding kits. The expressions of ferroptosis-negative regulation genes (GPX4 and SLC7A11) were determined by qRT-PCR and western blot. Molecular interactions were analyzed by RNA pull-down, RIP, ChIP, and dual-luciferase reporter assays. The effects of ITGB2-AS1 silencing on NSCLC cisplatin resistance in vivo were elevated by the tumor xenograft experiment. ITGB2-AS1 expression was increased in NSCLC patients and cisplatin-resistant NSCLC cells, which was positively correlated with ferroptosis-negative regulation genes. ITGB2-AS1 knockdown suppressed resistant cell proliferation and promoted cell apoptosis and ferroptosis. ITGB2-AS1 increased NAMPT expression by binding to FOSL2, thereby repressing p53 expression. The ITGB2-AS1 knockdown also inhibited NSCLC cisplatin resistance in vivo. ITGB2-AS1 promoted NSCLC cisplatin resistance by inhibiting p53-mediated ferroptosis via activating the FOSL2/NAMPT axis.

Dual inhibition of IDO1/TDO2 enhances anti-tumor immunity in platinum-resistant non-small cell lung cancer

BackgroundThe impact of non-small cell lung cancer (NSCLC) metabolism on the immune microenvironment is not well understood within platinum resistance. We have identified crucial metabolic differences between cisplatin-resistant (CR) and cisplatin-sensitive (CS) NSCLC cells with elevated indoleamine 2,3-dioxygenase-1 (IDO1) activity in CR, recognized by increased kynurenine (KYN) production.MethodsCo-culture, syngeneic, and humanize mice models were utilized. C57BL/6 mice were inoculated with either Lewis lung carcinoma mouse cells (LLC) or their platinum-resistant counterpart (LLC-CR) cells. Humanized mice were inoculated with either A (human CS cells) or ALC (human CR cells). Mice were treated with either IDO1 inhibitor or TDO2 (tryptophan 2,3-dioxygenase-2) inhibitor at 200 mg/kg P.O. once a day for 15 days; or with a new-in-class, IDO1/TDO2 dual inhibitor AT-0174 at 170 mg/kg P.O. once a day for 15 days with and without anti-PD1 antibody (10 mg/kg, every 3 days). Immune profiles and KYN and tryptophan (TRP) production were evaluated.ResultsCR tumors exhibited a more highly immunosuppressive environment that debilitated robust anti-tumor immune responses. IDO1-mediated KYN production from CR cells suppressed NKG2D on immune effector natural killer (NK) and CD8+ T cells and enhanced immunosuppressive populations of regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs). Importantly, while selective IDO1 inhibition attenuated CR tumor growth, it concomitantly upregulated the TDO2 enzyme. To overcome the compensatory induction of TDO2 activity, we employed the IDO1/TDO2 dual inhibitor, AT-0174. Dual inhibition of IDO1/TDO2 in CR mice suppressed tumor growth to a greater degree than IDO1 inhibition alone. Significant enhancement in NKG2D frequency on NK and CD8+ T cells and a reduction in Tregs and MDSCs were observed following AT-1074 treatment. PD-L1 (programmed death-ligand-1) expression was increased in CR cells; therefore, we assessed dual inhibition + PD1 (programmed cell death protein-1) blocking and report profound anti-tumor growth and improved immunity in CR tumors which in turn extended overall survival in mice.ConclusionOur study reports the presence of platinum-resistant lung tumors that utilize both IDO1/TDO2 enzymes for survival, and to escape immune surveillance as a consequence of KYN metabolites. We also report early in vivo data in support of the potential therapeutic efficacy of the dual IDO1/TDO2 inhibitor AT-0174 as a part of immuno-therapeutic treatment that disrupts tumor metabolism and enhances anti-tumor immunity.

Abstract 4912: Anticancer activity of Hsp90 inhibitor AUY922 in nasopharyngeal carcinoma and non-small cell lung cancer cells

Abstract Introduction: Nasopharyngeal carcinoma (NPC) and non-small cell lung cancer (NSCLC) are two of the most prevalent cancers in Southern China. Although cisplatin therapy may be initially successful, its effectiveness is often significantly reduced in patients with relapsed disease. There is an urgent need to overcome cisplatin resistance in the treatment of NPC and NSCLC. Luminespib (AUY922) is an experimental drug candidate for the treatment of cancer. It is an inhibitor of heat shock protein 90 (Hsp90), a chaperone protein that plays a role in modifying a variety of proteins involved in tumorigenesis. Hsp90 inhibitors have demonstrated potent activity in preclinical testing and clinical trials against various cancer types. We sought to investigate the preclinical efficacy of AUY922 and evaluate its anticancer effect in cisplatin-resistant NPC and NSCLC cells. Materials and Methods: Two NPC cells (HK1 and Hone1), four NSCLC cells (A549, SW900, NCI-H1975, and HCC4006), one normal lung cells (CCD11Lu), two cisplatin-resistant NPC cells (HK1-R and Hone1-R), and one cisplatin-resistant NSCLC cells (A549-R) were cultured and treated with 100 nM AUY922 for 48 hours. A cell proliferation assay was performed in triplicate to determine the antiproliferative effects of AUY922 on cancer cells. Flow cytometry was used for cell cycle analysis. The apoptotic cells were evaluated by Annexin V and Western blot analysis. Nude mice were used to test the effects of intraperitoneal injection of AUY922 on tumor growth. Results: We found that AUY922 significantly inhibited in vitro growth in all the two NPC (44% and 40%) and four NSCLC (53%, 77%, 50%, and 62%) cells in comparison to the normal lung cells (4%). The two cisplatin-resistant NPC cells (63% and 37%) also showed significant inhibition of viability after treatment with AUY922. However, there was only a slightly reduced viability in the cisplatin-resistant NSCLC cells (14%). Flow cytometry revealed that AUY922 induced G2/M and S phase arrest in HK1 and HK1-R cells. On the other hand, AUY922 also induced pro-apoptotic peaks in A549, A549-R, Hone1, and Hone1-R cells. Interestingly, Annexin V and Western blot analysis showed that cell death was not caused by apoptosis. In vivo, both AUY922 alone and the combination of AUY922 with cisplatin treatments inhibited NPC and NSCLC tumor growth without significant weight loss. In addition, the administration of AUY922 significantly reduced NPC and NSCLC tumor growth in the cisplatin-resistant mouse models. Conclusion: AUY922 exhibits potent anticancer activities in vitro and in vivo. These findings provide evidence that AUY922 could be useful for the treatment of NPC and NSCLC as a single agent or in combination with cisplatin. Most importantly, our results provide a preclinical proof of concept for the efficacy of AUY922 in cisplatin-resistant NPC and NSCLC treatment. Citation Format: William C. Cho, Chi F. Wong. Anticancer activity of Hsp90 inhibitor AUY922 in nasopharyngeal carcinoma and non-small cell lung cancer cells. [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 4912.

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.

ELF1 suppresses autophagy to reduce cisplatin resistance via the miR-152-3p/NCAM1/ERK axis in lung cancer cells.

Resistance to chemotherapeutic drugs limits the efficacy of chemotherapy in non-small cell lung cancer (NSCLC). Autophagy is an essential mechanism which involves in drug resistance. Our previous research has revealed that miR-152-3p represses NSCLC progression. However, the mechanism of miR-152-3p in autophagy-mediated chemoresistance in NSCLC remains unclear. Cisplatin-resistant cell lines (A549/DDP and H446/DDP) were transfected with related vectors and subjected to cisplatin, autophagy inhibitor, activator, or extracellular signal-regulated kinase (ERK) activator. Flow cytometry, CCK8 and colony formation assays were performed for testing apoptosis and cell viability. The related RNAs or proteins were detected by qRT-PCR or Western blot. Chromatin immunoprecipitation, luciferase reporter assay or RNA immunoprecipitation were used for validating the interaction between miR-152-3p and ELF1 or NCAM1. Co-IP verified the binding between NCAM1 and ERK. The role of miR-152-3p in cisplatin resistance of NSCLC was also validated in vivo. The results showed that miR-152-3p and ELF1 were decreased in NSCLC tissues. miR-152-3p reversed cisplatin resistance by inhibiting autophagy through NCAM1. NCAM1 promoted autophagy through the ERK pathway and facilitated cisplatin resistance. ELF1 positively regulated miR-152-3p level by directly interacting with miR-152-3p promoter. miR-152-3p targeted NCAM1 to regulate NCAM1 level and then affected the binding of NCAM1 to ERK1/2. ELF1 inhibited autophagy and reversed cisplatin resistance through miR-152-3p/NCAM1. miR-152-3p inhibited autophagy and cisplatin resistance of xenograft tumor in mice. In conclusion, our study revealed that ELF1 inhibited autophagy to attenuate cisplatin resistance through the miR-152-3p/NCAM1/ERK pathway in H446/DDP and A549/DDP cells, suggesting a potential novel treatment strategy for NSCLC.

Repurposing of triamterene as a histone deacetylase inhibitor to overcome cisplatin resistance in lung cancer treatment.

Cisplatin is the core chemotherapeutic drug used for first-line treatment of advanced non-small cell lung cancer (NSCLC). However, drug resistance is severely hindering its clinical efficacy. This study investigated the circumvention of cisplatin resistance by repurposing non-oncology drugs with putative histone deacetylase (HDAC) inhibitory effect. A few clinically approved drugs were identified by a computational drug repurposing tool called "DRUGSURV" and evaluated for HDAC inhibition. Triamterene, originally indicated as a diuretic, was chosen for further investigation in pairs of parental and cisplatin-resistant NSCLC cell lines. Sulforhodamine B assay was used to evaluate cell proliferation. Western blot analysis was performed to examine histone acetylation. Flow cytometry was used to examine apoptosis and cell cycle effects. Chromatin immunoprecipitation was conducted to investigate the interaction of transcription factors to the promoter of genes regulating cisplatin uptake and cell cycle progression. The circumvention of cisplatin resistance by triamterene was further verified in a patient-derived tumor xenograft (PDX) from a cisplatin-refractory NSCLC patient. Triamterene was found to inhibit HDACs. It was shown to enhance cellular cisplatin accumulation and potentiate cisplatin-induced cell cycle arrest, DNA damage, and apoptosis. Mechanistically, triamterene was found to induce histone acetylation in chromatin, thereby reducing the association of HDAC1 but promoting the interaction of Sp1 with the gene promoter of hCTR1 and p21. Triamterene was further shown to potentiate the anti-cancer effect of cisplatin in cisplatin-resistant PDX in vivo. The findings advocate further clinical evaluation of the repurposing use of triamterene to overcome cisplatin resistance.

YTHDC2-mediated m6A mRNA modification of Id3 suppresses cisplatin resistance in non-small cell lung cancer.

The methylation of adenosines at the N6 position (N6-methyladenosine; m6A) is one of the most conserved internal RNA modifications. m6A can modulate the expression of oncogenes or tumor suppressor genes, as well as m6A levels and the expression and activity of m6A enzymes, thus influencing tumor progression and therapeutic response. This study investigates the role of YTHDC2-mediated m6A messenger RNA (mRNA) modification of Id3 in controlling cisplatin resistance in non-small cell lung cancer (NSCLC). The expression of the m6A reader protein YTHDC2 was detected in an NSCLC cisplatin-resistant cell line (A549/DDP) using real-time fluorescence quantitative polymerase chain reaction (qPCR). YTHDC2 overexpression plasmids were constructed and transfected into A549/DDP and A549 cells respectively. We performed qPCR and western blot (WB) to detect changes in YTHDC2 and Id3 expression, and the effects of YTHDC2 overexpression on proliferation, apoptosis, invasion, and migration of drug-resistant cells were assessed by cell counting kit-8 (CCK-8), flow cytometry, and transwell and scratch assays. The m6A modification of Id3 by YTHDC2 was clarified by m6A-immunoprecipitation-PCR (m6A-IP-PCR) assay. The CLIPdb online database predicted that YTHDC2 might bind to Id3. The results of qPCR showed that YTHDC2 was downregulated in the NSCLC cisplatin-resistant cell line A549/DDP compared to the cisplatin-sensitive cell line A549. Overexpression of YTHDC2 increased the expression of Id3, and the methylation inhibitor 3-deazaadenosine abrogated the regulatory effect of YTHDC2 on Id3. YTHDC2 overexpression significantly inhibited A549/DDP cell proliferation, migration, and invasion, and promoted apoptosis by synergistically promoting the effects of Id3. m6A-IP-PCR analysis revealed that YTHDC2 could inhibit the m6A level of Id3 mRNA. To regulate the activity of Id3, YTHDC2 requires modifications to m6A, which ultimately inhibit cisplatin resistance in NSCLC.

CircANKRD28 inhibits cisplatin resistance in non-small-cell lung cancer through the miR-221-3p/SOCS3 axis.

Non-small-cell lung cancer (NSCLC) is a common cancer. Chemotherapeutic drug resistance limits the therapeutic effect of NSCLC and leads to a poor prognosis. As a result, new specific targets may be better identified by studying the mechanism of drug resistance to cisplatin in NSCLC. In the present study, we performed a quantitative real-time polymerase chain reaction and western blotting to detect mRNA and protein levels. The proliferation of cells was analyzed by a Cell Counting Kit-8 and colony formation assays. Cell invasion was measured via the Transwell assay. A scratch assay was performed to measure cell migration in cisplatin (DDP)-resistant NSCLC cells. Apoptosis of cells was examined using flow cytometry. We found that circANKRD28 was notably decreased in NSCLC. The results showed that circANKRD28 expression was not affected, and its half-life was more than 12 h. Functional experiments revealed that circANKRD28 overexpression inhibited DDP resistance in NSCLC cells in vitro. Mechanistic findings demonstrated that circANKRD28 regulated tumor cell progression and DDP sensitivity through the miR-221-3p/SOCS3 axis. The present study revealed the regulatory effects and molecular mechanism of circANKRD28 on the development and cisplatin resistance in NSCLC, which may provide experimental basis and theoretical support to identify new targets for therapy of DDP resistance in NSCLC.

Phosphorylation of IGFBP-3 by Casein Kinase 2 Blocks Its Interaction with Hyaluronan, Enabling HA-CD44 Signaling Leading to Increased NSCLC Cell Survival and Cisplatin Resistance.

Cisplatin is a platinum agent used in the treatment of non-small cell lung cancer (NSCLC). Much remains unknown regarding the basic operative mechanisms underlying cisplatin resistance in NSCLC. In this study, we found that phosphorylation of IGFBP-3 by CK2 (P-IGFBP-3) decreased its binding to hyaluronan (HA) but not to IGF-1 and rendered the protein less effective at reducing cell viability or increasing apoptosis than the non-phosphorylated protein with or without cisplatin in the human NSCLC cell lines, A549 and H1299. Our data suggest that blocking CD44 signaling augmented the effects of cisplatin and that IGFBP-3 was more effective at inhibiting HA-CD44 signaling than P-IGFBP-3. Blocking CK2 activity and HA-CD44 signaling increased cisplatin sensitivity and more effectively blocked the PI3K and AKT activities and the phospho/total NFκB ratio and led to increased p53 activation in A549 cells. Increased cell sensitivity to cisplatin was observed upon co-treatment with inhibitors targeted against PI3K, AKT, and NFκB while blocking p53 activity decreased A549 cell sensitivity to cisplatin. Our findings shed light on a novel mechanism employed by CK2 in phosphorylating IGFBP-3 and increasing cisplatin resistance in NSCLC. Blocking phosphorylation of IGFBP-3 by CK2 may be an effective strategy to increase NSCLC sensitivity to cisplatin.

A Systems Biology Approach for Addressing Cisplatin Resistance in Non-Small Cell Lung Cancer.

Translational research in medicine, defined as the transfer of knowledge and discovery from the basic sciences to the clinic, is typically achieved through interactions between members across scientific disciplines to overcome the traditional silos within the community. Thus, translational medicine underscores 'Team Medicine', the partnership between basic science researchers and clinicians focused on addressing a specific goal in medicine. Here, we highlight this concept from a City of Hope perspective. Using cisplatin resistance in non-small cell lung cancer (NSCLC) as a paradigm, we describe how basic research scientists, clinical research scientists, and medical oncologists, in true 'Team Science' spirit, addressed cisplatin resistance in NSCLC and identified a previously approved compound that is able to alleviate cisplatin resistance in NSCLC. Furthermore, we discuss how a 'Team Medicine' approach can help to elucidate the mechanisms of innate and acquired resistance in NSCLC and develop alternative strategies to overcome drug resistance.

In situ oxidative polymerization of platinum(iv) prodrugs in pore-confined spaces of CaCO3 nanoparticles for cancer chemoimmunotherapy.

Drug resistance and metastases are the leading causes of death in clinics. To overcome this limitation, there is an urgent need for new therapeutic agents and drug formulations that are able to therapeutically intervene by non-traditional mechanisms. Herein, the physical adsorption and oxidative polymerization of Pt(iv) prodrugs in pore-confined spaces of CaCO3 nanoparticles is presented, and the nanomaterial surface was coated with DSPE-PEG2000-Biotin to improve aqueous solubility and tumor targeting. While the nanoparticle scaffold remained stable in an aqueous solution, it quickly degraded into Ca2+ in the presence of acid and into cisplatin in the presence of GSH. The nanoparticles were found to interact in cisplatin-resistant non-small lung cancer cells by a multimodal mechanism of action involving mitochondrial Ca2+ overload, dual depletion of GSH, nuclear DNA platination, and amplification of ROS and lipid peroxide generation, resulting in triggering cell death by a combination of apoptosis, ferroptosis and immunogenic cell death in vitro and in vivo. This study could present a novel strategy for the treatment of drug-resistant and metastatic tumors and therefore overcome the limitations of currently used therapeutic agents in the clinics.