Increased Drug Sensitivity Research Articles

TRIM21-mediated ubiquitination and phosphorylation of ERK1/2 promotes cell proliferation and drug resistance in pituitary adenomas.

Pituitary adenomas (PAs) are common intracranial tumors and TRIM family plays a crucial role in cell proliferation, and therapeutic resistance of tumors. However, the role of the TRIM family in PAs is not well recognized. CRISPR screening explored the role of TRIM family in the cell proliferation and drug resistance in PAs. In vitro and in vivo experiments were performed to evaluate the effects of Tripartite Motif Containing 21 (TRIM21). RNA-sequencing, mass spectrometry, immunoprecipitation and ubiquitination experiments were performed to explore the molecular mechanism. NanoBiT assays were used to screen the drugs reducing TRIM21 expression. CRISPR-Cas9 screens identified that TRIM21 facilitated cell proliferation and drug resistance in PAs. Mechanistically, TRIM21 interacted with ERK1/2 through PRY-SPRY domain, leading to ERK1/2 K27-linked ubiquitination. The ERK1/2 ubiquitination promotes the interaction between ERK1/2 and MEK1/2, thereby facilitating the phosphorylation of ERK1/2. However, an excess presence of TRIM21 supressed the phosphorylation of ERK1/2 and cell proliferation via activating ERK1/2 negative feedback pathways. Importantly, TRIM21 was upregulated in dopamine-resistant prolactinomas and cabergoline-resistant MMQ cells. Furthermore, drug screening identified that Fimepinostat and Quisinostat, can reduce the protein levels of TRIM21, inhibit tumor progression, and increase drug sensitivity. TRIM21 may represent a therapeutic target for tumors, and inhibiting TRIM21 could be a potential strategy for tumor treatment.

A comprehensive investigation of associations between cell death pathways and molecular and clinical features in pan-cancer.

Regulated cell death (RCD) pathways play significant roles in tumorigenesis. However, systematic investigation into correlations between RCD and various molecular and clinical features, particularly anti-tumor immunity and immunotherapy response in pan-cancer remains lacking. Using the single-sample gene set enrichment analysis, we quantified the activities of six RCD pathways (apoptosis, autophagy, ferroptosis, cuproptosis, necroptosis, and pyroptosis) in each cancer specimen. Then, we explored associations of these six RCD pathways with tumor immunity, genomic instability, tumor phenotypes and clinical features, and responses to immunotherapy and targeted therapies in pan-cancer by statistical analyses. Our results showed that the RCD (except autophagy) activities were oncogenic signatures, as evidenced by their hyperactivation in late stage or metastatic cancer patients, positive correlations with tumor proliferation, stemness, genomic instability and intratumor heterogeneity, and correlation with worse survival outcomes in cancer. In contrast, autophagy was a tumor suppressive signature as its associations with molecular and clinical features in cancer shows an opposite pattern compared to the other RCD pathways. Furthermore, heightened RCD (except cuproptosis) activities were correlated with increased sensitivity to immune checkpoint inhibitors. Additionally, elevated activities of pyroptosis, autophagy, cuproptosis and necroptosis were associated with increased drug sensitivity in a broad spectrum of anti-tumor targeted therapies, while the elevated activity of ferroptosis was correlated with decreased sensitivity to numerous targeted therapies. RCD (except autophagy) activities correlate with unfavorable cancer prognosis, while the autophagy activity correlate with favorable clinical outcomes. RCD (except cuproptosis) activities are positive biomarkers for anti-tumor immunity and immunotherapy response.

Expression of MxA in esophageal cancer cell lines can influence sensitivity to chemotherapeutic agents but this does not require apoptosis.

Esophageal cancer is a poor prognosis cancer characterized by intrinsic or acquired resistance to chemotherapeutic agents. The primary determinants of treatment failure are unknown. Expression of an anti-viral protein, myxovirus resistance protein A (MxA) is de-regulated in many cancers, including esophageal cancer, and its activity has been linked to apoptosis. This study has assessed whether MxA expression can influence the response of esophageal cancer cells to the chemotherapeutic agents 5-fluorouracil (5-FU) or oxaliplatin. MxA protein was differentially expressed in a panel of five esophageal cancer cell lines. KYSE450 and KYSE140 cells did not express MxA and were apoptosis incompetent. FLO-1, KYSE270, and OE21 cells expressed MxA, were more drug-sensitive and were apoptosis competent. MxA was artificially overexpressed in cell lines with no endogenous expression (KYSE450 and KYSE140). This increased the resistance of KYSE450 but not KYSE140 cells. Both cell lines remained apoptosis incompetent. We then evaluated siRNA knockdown of MxA in FLO-1 cells and CRISPR knockout in OE21 cells. Knockdown of MxA significantly increased drug sensitivity and caspase-3 activation in FLO-1 cells. OE21-MX1KO cells were also more drug-sensitive, but in contrast to FLO-1 cells, caspase-3 activation was reduced. Collectively these data indicate that MxA can promote resistance to chemotherapy, but this does not always correspond with effects on apoptosis. Effects on apoptosis are cell line specific, suggesting that other co-operating pathways determine the overall impact of MxA. Importantly, in cancer cells that overexpress the protein, drug sensitivity can be improved by interfering with MxA.

Combined targeting of Hedgehog/GLI1 and Wnt/β-catenin pathways in mantle cell lymphoma.

Mantle cell lymphoma (MCL) is a rare and aggressive form of non-Hodgkin lymphoma. Challenges in its treatment include relapse, drug resistance, and a short survival period. The Hedgehog/GLI1 (Hh/GLI1) and Wnt/β-catenin pathways are crucial in cancer cell proliferation, survival, and drug resistance, making them significant targets for anticancer research. This study aimed to assess the effectiveness of combining inhibitors for both pathways against MCL and investigate the underlying molecular mechanisms. The co-expression of key proteins from the Hh/GLI1 and Wnt/β-catenin pathways was observed in MCL. Targeting the Hh/GLI1 pathway with the GLI1 inhibitor GANT61 and the Wnt/β-catenin pathway with the CBP/β-catenin transcription inhibitor ICG-001, dual-target therapy was demonstrated to synergistically suppressed the activity of MCL cells. This approach promoted MCL cell apoptosis, induced G0/G1 phase blockade, decreased the percentage of S-phase cells, and enhanced the sensitivity of MCL cells to the drugs adriamycin and ibrutinib. Both GANT61 and ICG-001 downregulated GLI1 and β-catenin while upregulating GSK-3β expression. The interaction between Hh/GLI1 and Wnt/β-catenin pathways was mediated by GANT61-dependent Hh/GLI1 inhibition. Moreover, GLI1 knockdown combined with ICG-001 synergistically induced apoptosis and increased drug sensitivity of MCL cells to doxorubicin and ibrutinib. GANT61 attenuated the overexpression of β-catenin and decreased the inhibition of GSK-3β in MCL cells. Overall, the combined targeting of both the Hh/GLI1 and Wnt/β-catenin pathways was more effective in suppressing proliferation, inducing G0/G1 cycle retardation, promoting apoptosis, and increasing drug sensitivity of MCL cells than mono treatments. These findings emphasize the potential of combinatorial therapy for treating MCL patients.

Identification and validation of basement membrane-associated gene AGRN as prognostic and immune-associated biomarkers in colorectal cancer patients.

Colorectal cancer (COCA) has a poor prognosis, with growing evidence implicating basement membranes (BMs) in cancer progression. Our goal was to investigate the role and predictive significance of BMs in COCA patients. We obtained BMs-related genes from cutting-edge research and used TCGA and GTEx databases for mRNA expression and patient information. Cox regression and LASSO regression were used for prognostic gene selection and risk model construction. We compared prognosis using Kaplan-Meier analysis and examined drug sensitivity differences. The CMAP dataset identified potential small molecule drugs. Invitro tests involved suppressing a crucial gene to observe its impact on tumour metastasis. We developed a 12 BMs-based approach, finding it to be an independent prognostic factor. Functional analysis showed BMs concentrated in cancer-associated pathways, correlating with immune cell infiltration and immune checkpoint activation. High-risk individuals exhibited increased drug sensitivity. AGRN levels were linked to decreased progression-free survival (p < 0.001). AGRN knockdown suppressed tumour growth and metastasis. Our study offers new perspectives on BMs in COCA, concluding that AGRN is a dependable biomarker for patient survival and prognosis.

Enhanced hepatotoxicity assessment through encapsulated HepG2 spheroids in gelatin hydrogel matrices: Bridging the gap from 2D to 3D culture

Conventional 2D drug screening often fails to accurately predict clinical outcomes. We present an innovative approach to improve hepatotoxicity assessment by encapsulating HepG2 spheroids in gelatin hydrogel matrices with different mechanical properties. Encapsulated spheroids exhibit sustained liver-specific functionality, enhanced expression of drug-metabolizing enzymes, and increased drug sensitivity compared to 2D cultures. The platform detects critical variations in drug response, with significant differences in IC50 values between 2D and spheroid cultures ranging from 1.3-fold to > 13-fold, particularly for acetaminophen. Furthermore, drug-metabolizing enzyme expression varies across hydrogel concentrations, suggesting a role for matrix mechanical properties in modulating hepatocyte function. This novel spheroid-hydrogel platform offers a transformative approach to hepatotoxicity assessment, providing increased sensitivity, improved prediction, and a more physiologically relevant environment. The use of such advanced in vitro models can accelerate drug development, reduce animal testing, and contribute to improved patient safety and clinical outcomes.

Overexpression of human DNA polymerase theta is a biomarker of aggressive and DNA repair-deficient papillary thyroid cancers

BackgroundDNA polymerase theta (POLQ) is an enzyme that repairs double-strand DNA breaks. POLQ is overexpressed in several cancer types, and increased expression is associated with a poor prognosis. Ablating POLQ function in vitro increases drug sensitivity to agents that cause double-strand DNA breaks, including chemotherapies and ionizing radiation. POLQ’s role in thyroid cancer remains poorly understood. MethodsExpression of POLQ and other genes of interest were analyzed in 513 papillary thyroid cancers (505 primary tumors and 8 metastatic lesions) and 59 normal thyroid samples available in the Cancer Genome Atlas. The Cancer Genome Atlas RNA and DNA sequencing data were queried with the Xena platform. The Recombination Proficiency Score was calculated to assess DNA repair efficiency. Other signaling events associated with thyroid tumorigenesis and clinical outcomes were analyzed. Univariate and multivariate analyses were performed. Treatment with the POLQ inhibitors ART558 and Novobiocin tested the effect of POLQ inhibition on in vitro thyroid cancer growth. ResultsPOLQ expression was increased in papillary thyroid cancers compared to normal thyroid tissue (P < .05). POLQ expression levels were inversely correlated with Recombination Proficiency Score levels (P < .05). POLQ expression was highest in tall cell papillary thyroid cancers and in metastases. Higher POLQ expression was also associated with dedifferentiation, BRAF signaling, and shorter progression-free intervals (P < .05). Treatment with POLQ inhibitors decreased in vitro thyroid cancer growth (P < .05). ConclusionThese findings suggest that increased POLQ expression could serve as a valuable clinical marker and a potential therapeutic target in the treatment of thyroid cancer.

CRTAC1 identified as a promising diagnosis and prognostic biomarker in lung adenocarcinoma

CRTAC1, one of the pyroptosis-related genes, has been identified as a protective factor in certain kinds of cancer, such as gastric adenocarcinoma and bladder cancer. The study aimed to investigate the role of CRTAC1 in lung adenocarcinoma (LUAD). LUAD datasets were obtained from Gene Expression Omnibus (GEO) database and The Cancer Genome Atlas (TCGA), pyroptosis-related genes from GeneCard. Limma package used to find differentially expressed genes (DEGs), least absolute shrinkage and selection operator (LASSO) regression and weighted genes co-expression network analysis (WGCNA) to identify CRTAC1 as hub gene. CRTAC1 expression was confirmed in a real-world cohort using quantitative polymerase chain reaction (qPCR) and Western Blot (WB) analyses. Cellular experiments were conducted to investigate CRTAC1’s potential oncogenic mechanisms. CRTAC1 mRNA expression was significantly lower in LUAD tissues (p < 0.05) and showed high accuracy in diagnosing LUAD. Reduced CRTAC1 expression was associated with a poor prognosis. Higher CRTAC1 expression correlated with increased immune cell infiltration. Individuals with high CRTAC1 expression showed increased drug sensitivity. Additionally, qPCR and WB analyses showed that CRTAC1 expression was lower in tumor tissue compared to adjacent normal tissue at both the RNA and protein levels. Upregulation of CRTAC1 significantly inhibited LUAD cell proliferation, invasion, and migration in cellular experiments. CRTAC1 has the potential to serve as a diagnostic and prognostic biomarker in LUAD.

Abstract 228: Patient-derived gbm organoids reflect tumour heterogeneity and treatment sensitivity in patients

Abstract Glioblastoma (GBM) is the most common and incurable adult primary brain tumour. Treatment resistance and relapse is the primary cause of death in GBM. Tumour heterogeneity is one of the significant determinants of treatment failure. Patient-derived cancer organoids have been shown to maintain genetic and phenotypic tumour features and recapitulate intratumoral heterogeneity. Here, we report the development and molecular characterisation of patient-derived GBM organoid (PGO) models to study treatment response to existing and new treatment combinations. GBM biopsies were dissociated, suspended in Cultrex, and cultured in a brain stem cell medium. PGOs were characterised by whole-exome (WES) single-cell karyotype (scKaryoSeq) and RNA sequencing. The IC-50 and viability of PGO upon temozolomide (TMZ) and small molecule inhibitors were determined. Gene expression profiling was performed before and after TMZ treatment. Single-cell spatial heterogeneity was determined using Multiplex Immunostaining of PGO and matched patient samples. PGOs were established with a success rate of 80% (n=31). WES analysis between PGOs from the same patient at multiple time points (1-3 months) showed high maintenance of Single Nucleotide Variants (92.3%-97.7%). In PGOs key somatic oncogene variants and copy number variations were retained compared to the primary tumour (58%-90%). scKaryoseq (N=7) of different clinical GBM subtypes showed a high degree of genetic heterogeneity, with some PGO having up to 10 subclones. Single-cell phenotypic landscaping of patient biopsies showed mixed cellular states maintained after long-term culture in the matched PGO. PGOs showed a differential response to TMZ, corresponding with MGMT methylation and patient mutation status. RNAseq of PGO revealed TMZ-responsive genes, including upregulation of the prognostic JUN kinase pathway. Combination treatment of a JUN kinase inhibitor and TMZ showed a synergistic effect. In addition, PGOs were screened for their sensitivity to clinically approved brain-penetrable small molecule inhibitors targeting key GBM driver pathways. Combining small molecular inhibitors of MEK/PI-3/CDK4/EGFR kinase strongly reduced cell viability and activation of cell death pathways. phosphoKinome screens detected compensatory pathway activation upon kinase inhibition (MEK/CDK4 inhibitor) in several PGO. Data will show novel kinase interaction pathways that increase drug sensitivity in PGO. These data show that PGOs can be used as a stable phenotypic and genetic representative of the patient's tumour and have the potential to function as patient avatars for adaptive treatment selection and actionable drug target discovery. Citation Format: Marc A. Vooijs, Linde Hoosemans, Jolanda Piepers, Maikel Verduin, Maxime Vanmechelen, Mike Van Heumen, Frederik De Smet, Ann Hoeben. Patient-derived gbm organoids reflect tumour heterogeneity and treatment sensitivity in patients [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 228.

RSM-CCD optimized hollow mesoporous silica nanospheres encapsulating sorafenib induce mitochondrial membrane potential mediated apoptotic cell death in non-small cell lung cancer

Hollow mesoporous silica nanoparticles (HMSNs) are considered appealing nanovehicles for drug delivery due to their exceptional drug loading and release potential. This study plans to synthesize HMSNs using a novel, quick, and economical procedure in co-relation with traditional mesoporous silica nanoparticles (MSNs) and optimize their synthesis by using the RSM-CCD approach. The influence of independent variables, i.e., CTAB (X1), TEOS (X2), and pH (X3), was evaluated by a 3-factorial design and ANOVA. RSM-CCD depicted the best synthesis formulation. CTAB: 0.3 g, TEOS: 3 ml, pH: 11.5. Optimized MSNs and HMSNs were characterized by DLS, XRD, SEM, FTIR, TEM, BET, XPS, and FE-SEM. Subsequently, hemocompatibility analysis revealed excellent compatibility of the nanosamples toward human RBCs. The drug loading efficiency of SF-MSNs and SF-HMSNs was 13.71 ± 0.33 % and 51.31 ± 0.94 %, respectively. A drug dissolution study revealed that sorafenib (SF) was released sustainably, with a cumulative release percentage of 67 % (HMSNs) and 77 % (MSNs) at 72 h, proving the superiority of SF-HMSNs over sustained release. In-vitro cell culture studies explored the anti-tumorigenic prospects of free and encapsulated SF. Cell cytotoxicity was assessed by MTT assay against A549 cells, indicating enhanced toxicity for optimized SF-HMSNs. The IC50 value substantially decreased from 10.5 to 5.8 μg/ml (a 1.8-fold decrease) after encapsulation. Additionally, In-vitro assays reflected MMP-mediated apoptotic cell death in A549 cells due to increased drug sensitivity and ROS generation. Collectively, these findings suggest that HMSNs are an ideal drug delivery vehicle due to the sustainable release of SF for NSCLC treatment.

It Takes Two to Tango: The Interplay between Prostate Cancer and Its Microenvironment from an Epigenetic Perspective.

Prostate cancer is the second most common cancer in men worldwide and is associated with high morbidity and mortality. Consequently, there is an urgent unmet need for novel treatment avenues. In addition to somatic genetic alterations, deviations in the epigenetic landscape of cancer cells and their tumor microenvironment (TME) are critical drivers of prostate cancer initiation and progression. Unlike genomic mutations, epigenetic modifications are potentially reversible. Therefore, the inhibition of aberrant epigenetic modifications represents an attractive and exciting novel treatment strategy for castration-resistant prostate cancer patients. Moreover, drugs targeting the epigenome also exhibit synergistic interactions with conventional therapeutics by directly enhancing their anti-tumorigenic properties by "priming" the tumor and tumor microenvironment to increase drug sensitivity. This review summarizes the major epigenetic alterations in prostate cancer and its TME, and their involvement in prostate tumorigenesis, and discusses the impact of epigenome-targeted therapies.

Magnoflorine inhibits cisplatin-induced protective autophagy by down-regulating HMGB1 and increases drug sensitivity in drug-resistant ovarian cancer cells

Magnoflorine inhibits cisplatin-induced protective autophagy by down-regulating HMGB1 and increases drug sensitivity in drug-resistant ovarian cancer cells

LINC00460 knockdown sensitizes cervical cancer to cisplatin by downregulating TGFBI.

The acquired resistance of cancer to cisplatin (DDP) limits the efficacy of chemotherapy. The prognostic value of long noncoding RNA (lncRNA) LINC00460 has been reported in cervical cancer. However, its effect on DDP sensitivity in cervical cancer remains poorly understood. In present study, LINC00460 was screened out through bioinformatics analysis. The expression levels of mRNAs and proteins were measured by reverse transcription-quantitative PCR (RT-qPCR) or western blot analysis. The sensitivity to DDP was investigated using an CCK8 assay. Cell apoptosis was determined by flow cytometry. The differentially expressed genes that were associated with the poor prognosis of cervical cancer were screened, and their correlations with LINC00460 expression were explored using Pearson's correlation analysis. Tumor xenograft model was used to assess the effect of LINC00460 knockdown on DDP sensitivity invivo. The interaction between miR-338-3p and LINC00460 or transforming growth factor β-induced protein (TGFBI) was confirmed by RNA immunoprecipitation (RIP) and luciferase reporter assays. LINC00460 expression was increased in cervical cancer tissues and cells. High expression of LINC00460 was associated with dismal prognosis in cervical cancer patients. Silencing of LINC00460 increased drug sensitivity and induced apoptosis in DDP-resistant-cervical cancer cells. LINC00460 knockdown enhanced DDP sensitivity in cervical cancer cells largely by downregulating TGFBI expression. LINC00460 knockdown enhanced the sensitivity of cervical cancer to DDP invivo, and this effect was partly mediated by the downregulation of TGFBI. LINC00460 positively regulated TGFBI expression, possibly by acting as a sponge of miR-338-3p. LINC00460 knockdown contributed to DDP sensitivity of cervical cancer by downregulating TGFBI, providing a novel mechanism underlying the acquisition of DDP sensitivity.

Reduced Proteolipid Protein 2 promotes endoplasmic reticulum stress-related apoptosis and increases drug sensitivity in acute myeloid leukemia.

The Proteolipid Protein 2 (PLP2), a protein in the Endoplasmic Reticulum (ER) membrane, has been reported to be highly expressed in various tumors. Previous studies have demonstrated that the reduced PLP2 can induce apoptosis and autophagy through ER stress-related pathways, leading to a decreased proliferation and aggressiveness. However, there is no research literature on the role of PLP2 in Acute Myeloid Leukemia (AML). PLP2 expression, clinical data, genetic mutations, and karyotype changes from GEO, TCGA, and timer2.0 databases were analyzed through the R packages. The possible functions and pathways of cells were explored through GO, KEGG, and GSEA enrichment analysis using the clusterProfiler R package. Immuno-infiltration analysis was conducted using the Cibersort algorithm and the Xcell R package. RT-PCR and western blot techniques were employed to identify the PLP2 expression, examine the knockdown effects in THP-1 cells, and assess the expression of genes associated with endoplasmic reticulum stress and apoptosis. Flow cytometry was utilized to determine the apoptosis and survival rates of different groups. PLP2 expression was observed in different subsets of AML and other cancers. Enrichment analyses revealed that PLP2 was involved in various tumor-related biological processes, primarily apoptosis and lysosomal functions. Additionally, PLP2 expression showed a strong association with immune cell infiltration, particularly monocytes. In vitro, the knockdown of PLP2 enhanced endoplasmic reticulum stress-related apoptosis and increased drug sensitivity in THP-1 cells. PLP2 could be a novel therapeutic target in AML, in addition, PLP2 is a potential endoplasmic reticulum stress regulatory gene in AML.

Targeting PKM2 improves the gemcitabine sensitivity of intrahepatic cholangiocarcinoma cells via inhibiting β-catenin signaling pathway

Gemcitabine is considered the standard first-line chemotherapeutic agent for patients with intrahepatic cholangiocarcinoma (ICC). However, its therapeutic efficacy is hampered by the development of chemoresistance. Pyruvate kinase M2 (PKM2), a crucial mediator of the final step in glycolysis, has been implicated in the origination and advancement of diverse malignancies. Its expression is increased in many tumor types and this may correlate with increased drug sensitivity. However, the specific effect of PKM2 on the gemcitabine sensitivity in ICC remains to be elucidated. In this research, we aimed to elucidate the role and functional significance of PKM2 in ICC, as well as the heightened susceptibility of ICC cells to gemcitabine by targeting PKM2 and the underlying molecular mechanisms. Immunohistochemical and immunofluorescence analyses revealed elevated expression of PKM2 in both tumor cells and macrophages in human ICC tissues. Reducing PKM2 levels significantly restrained the proliferation of tumor cells, impeded cell cycle advance, induced programmed cell death, and suppressed metastasis. In addition, knockdown or pharmacological inhibition of PKM2 could enhance the response of ICC cells to gemcitabine in vitro. Interestingly, conditioned medium co-culture system suggested that conditioned medium from M2 macrophages increased gemcitabine sensitivity of ICC cells. However, silencing PKM2 or pharmacological inhibition of PKM2 in M2 macrophages did not ameliorate the gemcitabine resistance mediated by M2 macrophages derived conditioned medium. Mechanistically, downregulation of PKM2 repressed the expression of β-catenin and its downstream transcriptional targets, thereby hindering the propagation of β-catenin signaling cascade. Finally, the results of the subcutaneous xenograft experiment in nude mice provided compelling evidence of a synergistic interaction between PKM2-IN-1 and gemcitabine in vivo. In summary, we reported that PKM2 may function as an advantageous target for increasing the sensitivity of ICC to gemcitabine treatment. Targeting PKM2 improves the gemcitabine sensitivity of ICC cells via inhibiting β-catenin signaling pathway.

SIX1 Downregulation Suppresses Self-renewal Capacity and THY1 Expression in Hepatocellular Carcinoma and SIX1 Dominate the Survival in Liver Cancer.

Sine oculis homeoprotein 1 exerts an essential role in embryonic development, and it was also identified to be reactivated in various types of mammalian cancer. The sine oculis homeoprotein 1 transcription factor was demonstrated to induce epithelial-mesenchymal transition, regulate crucial genes associated with cancer progression, and increase the oncogenic potential of cells. Therefore, the present study aimed to identify the role of sine oculis homeoprotein 1 in cancer. Sine oculis homeoprotein 1 gene expression was tested with real-time quantitative polymerase chain reaction (PCR) in different cancer types. Sine oculis homeoprotein 1 expression was suppressed by short hairpin RNA transduction in the SNU398 hepatocellular carcinoma cell line. The effects of sine oculis homeoprotein 1 on cell proliferation, drug resistance, and sphere formation were assessed in shSIX1 cells. Immunohistochemical and in silico analyses were performed to determine the prognostic role of sine oculis homeoprotein 1 expression. The upregulated expression levels of sine oculis homeoprotein 1 were revealed to be correlated with the stage of the disease in breast, colon, and liver cancer, with liver cancer exhibiting the highest expression profile. Sine oculis homeoprotein 1 downregulation significantly affected cell proliferation and suppressed sorafenib resistance and sphere-forming ability. Furthermore, sine oculis homeoprotein 1 knockdown cells were identified to have decreased CD90 levels, essential for cancer stem cell properties. Finally, sine oculis homeoprotein 1 expression was a CD90-independent biomarker for the clinical prognosis of liver cancer. The results of this study showed that the knockdown of sine oculis homeoprotein 1 expression might help to prevent hepatocarcinogenesis by increasing drug sensitivity and controlling tumor sphere formation. Overall, these results indicated that sine oculis homeoprotein 1 expression might be useful as a diagnostic marker for patients with hepatocellular carcinoma.

T-cell exhaustion prediction algorithm in tumor microenvironment for evaluating prognostic stratification and immunotherapy effect of esophageal cancer.

Esophageal cancer (EC) is a common digestive malignancy that ranks sixth in cancer deaths, with a 5-year survival rate of 15%-25%. As a result, reliable prognostic biomarkers are required to accurately predict the prognosis of EC. T-cell exhaustion (TEX) is associated with poorer prognosis and immune infiltration in EC. In this study, nine risk genes were finally screened to constitute the prognostic model using least absolute shrinkage and selection operator analysis. Patients were divided into two groups based on the expression of the TEX-related genes: high-risk group and low-risk group. The expression of TEX-related genes differed significantly between the two groups. The findings revealed that the risk model developed was highly related to the clinical prognosis and amount of immune cell infiltration in EC patients. It was also significantly correlated with the therapeutic sensitivity of multiple chemotherapeutic agents in EC patients. Subsequently, we successfully constructed drug-resistant cell lines KYSE480/CDDP-R and KYSE180/CDDP-R to verify the correlation between PD-1 and drug resistance in EC. Then, we examined the mRNA and protein expression levels of PD-1 in parental and drug-resistant cells using qPCR and WB. It was found that the expression level of PD-1 was significantly increased in the plasma red of drug-resistant cells. Next, we knocked down PD-1 in drug-resistant cells and found that the resistance of EC cells to CDDP was significantly reduced. And the proportion of apoptotic cells in cells treated with 6 μM CDDP for 24 h was significantly in increase. The TEX-based risk model achieved good prediction results for prognosis prediction in EC patients. And it was also significantly associated with the level of immune cell infiltration and drug therapy sensitivity of EC patients. Additionally, the downregulation of PD-1 may be associated with increased drug sensitivity in EC and enhanced T-cell infiltration. The high-risk group had lower TIDE scores, indicating that the high-risk group benefits more after receiving immunotherapy. Thus, the TEX-based risk model can be used as a novel tumor prognostic biomarker.

Microsatellite instability states serve as predictive biomarkers for tumors chemotherapy sensitivity

There is an urgent need for markers to predict the efficacy of different chemotherapy drugs. Herein, we examined whether microsatellite instability (MSI) status can predict tumor multidrug sensitivity and explored the underlying mechanisms. We downloaded data from several public databases. Drug sensitivity was compared between the high microsatellite instability (MSI-H) and microsatellite-stable/low microsatellite instability (MSS/MSI-L) groups. In addition, we performed pathway enrichment analysis and cellular chemosensitivity assays to explore the mechanisms by which MSI status may affect drug sensitivity and assessed the differences between drug-treated and control cell lines. We found that multiple MSI-H tumors were more sensitive to a variety of chemotherapy drugs than MSS/MSI-L tumors, and especially for CRC, chemosensitivity is enhanced through the downregulation of DDR pathways such as NHEJ. Additional DNA damage caused by chemotherapeutic drugs results in further downregulation of DDR pathways and enhances drug sensitivity, forming a cycle of increasing drug sensitivity.

Neuroglobin inhibits pancreatic cancer proliferation and metastasis by targeting the GNAI1/EGFR/AKT/ERK signaling axis

Pancreatic cancer is an extremely aggressive malignancy with a very disappointing prognosis. Neuroglobin (NGB), a member of the globin family, has been demonstrated to have a significant role in a variety of tumor forms. The possible role of NGB as a tumor suppressor gene in pancreatic cancer was investigated in this work. Information from the public dataset TCGA combined with GTEx was used to analyze the finding that NGB was commonly downregulated in pancreatic cancer cell lines and tissues, correlating with patient age and prognosis. The expression of NGB in pancreatic cancer was investigated via RT-PCR, qRT-PCR, and Western blot experiments. In-vitro and in-vivo assays, NGB elicited cell cycle arrest in the S phase and apoptosis, hindered migration and invasion, reversed the EMT process, and suppressed cell proliferation and development. The mechanism of action of NGB was predicted via bioinformatics analysis and validated using Western blot and co-IP experiments revealed that NGB inhibited the EGFR/AKT/ERK pathway by binding to and reducing expression of GNAI1 and p-EGFR. In addition, pancreatic cancer cells overexpressing NGB showed increased drug sensitivity to gefitinib (EGFR-TKI). In conclusion, NGB inhibits pancreatic cancer progression by specifically targeting the GNAI1/EGFR/AKT/ERK signaling axis.

Abstract 412: Drug combination screen identifies pemigatinib, an FGFR inhibitor, as a mechanism to overcome KRASG12C inhibitor resistance in lung cancer

Abstract Background: Lung cancer is one of the most common tumors, accounting for approximately 1.8 million deaths worldwide in 2020. KRAS is a frequently mutated oncogene, with mutations reported in roughly 20-25% of non-small cell lung cancer cases. Specifically, KRAS mutations at amino acid 12, resulting in a glycine to cysteine (G12C) substitution, occur in approximately 13% and 3% of lung and colon cancers, respectively, and less frequently in other solid tumors. Recently, the development of covalent KRASG12C inhibitors has shown meaningful anticancer activity in patients. However, many patients with KRASG12C do not respond and/or develop resistance to single-agent treatment. Here we investigate combination therapies that may overcome resistance and broaden patient response to KRASG12C inhibitors. Methods: In vitro preclinical KRASG12C models including lung and colon cancer cell lines were treated with a panel of small molecule and covalent KRASG12C inhibitors. The activity of single-agent versus combination treatments was measured in cell viability assays, and screen hits were validated by in vitro mechanism of action studies. Results: A curated set of 152 compounds was used in combination with screen monitoring cell-viability assays across 12 KRAS mutant lung and colon cancer cell lines. Compounds tested included kinase inhibitors targeting oncogenic signaling pathways, epigenetics modifiers, regulators of apoptosis, chemotherapeutics, and other anticancer agents. The screen identified synergy between covalent KRASG12C and several other inhibitors including those for FGFR, EGFR, and SHP2. Notably, pemigatinib, a potent and selective FGFR1-3 inhibitor, had a significantly high Bliss synergy score. Selectivity and siRNA knockdown experiments were performed to identify the specific FGFR isoform involved in synergistic anticancer activity. Inhibition of FGFR1 activity was shown to be essential, whereas an FGFR2-3 specific inhibitor demonstrated only modest activity in combination with KRASG12C inhibitors. Additionally, FGFR1 knockdown combined with KRASG12C inhibition resulted in increased drug sensitivity; in contrast, knockdown of other FGFR family members did not demonstrate similar increase in sensitivity to KRASG12C inhibition. Conclusions: Cell-viability combination screening identified strong synergy between KRASG12C covalent inhibitors and the FGFR1-3 inhibitor pemigatinib in KRASG12C cancer cell lines. The synergistic effect of pemigatinib and KRASG12C inhibition was notably strongest in mesenchymal cancer cell lines. This effect was further validated in in vitro selectivity and siRNA studies. Together, our results support pemigatinib as a promising agent for combination therapy with KRAS inhibitors in lung cancer. Citation Format: Angela Abdollahi, Margaret Favata, Darlise DiMatteo, Sean Schuette, Erika Boarder, Mark Rupar, Ricardo Macarron, Aidan Gilmartin, Hui Wang, Alejandro Amador-Arjona. Drug combination screen identifies pemigatinib, an FGFR inhibitor, as a mechanism to overcome KRASG12C inhibitor resistance in lung cancer [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 412.