Sensitivity Of Cells Research Articles

METTL5 promotes gastric cancer progression via sphingomyelin metabolism

BACKGROUND The treatment of gastric cancer (GC) has caused an enormous social burden worldwide. Accumulating studies have reported that N6-methyladenosine (m6A) is closely related to tumor progression. METTL5 is a m6A methyltransferase that plays a pivotal role in maintaining the metabolic stability of cells. However, its aberrant regulation in GC has not been fully elucidated. AIM To excavate the role of METTL5 in the development of GC. METHODS METTL5 expression and clinicopathological characteristics were analyzed via The Cancer Genome Atlas dataset and further verified via immunohistochemistry, western blotting and real-time quantitative polymerase chain reaction in tissue microarrays and clinical samples. The tumor-promoting effect of METTL5 on HGC-27 and AGS cells was explored in vitro by Cell Counting Kit-8 assays, colony formation assays, scratch healing assays, transwell assays and flow cytometry. The tumor-promoting role of METTL5 in vivo was evaluated in a xenograft tumor model. The EpiQuik m6A RNA Methylation Quantification Kit was used for m6A quantification. Next, liquid chromatography-mass spectrometry was used to evaluate the association between METTL5 and sphingomyelin metabolism, which was confirmed by Enzyme-linked immunosorbent assay and rescue tests. In addition, we investigated whether METTL5 affects the sensitivity of GC cells to cisplatin via colony formation and transwell experiments. RESULTS Our research revealed substantial upregulation of METTL5, which suggested a poor prognosis of GC patients. Increased METTL5 expression indicated distant lymph node metastasis, advanced cancer stage and pathological grade. An increased level of METTL5 correlated with a high degree of m6A methylation. METTL5 markedly promotes the proliferation, migration, and invasion of GC cells in vitro . METTL5 also promotes the growth of GC in animal models. METTL5 knockdown resulted in significant changes in sphingomyelin metabolism, which implies that METTL5 may impact the development of GC via sphingomyelin metabolism. In addition, high METTL5 expression led to cisplatin resistance. CONCLUSION METTL5 was found to be an oncogenic driver of GC and may be a new target for therapy since it facilitates GC carcinogenesis through sphingomyelin metabolism and cisplatin resistance.

Ras-Targeting Stabilized Peptide Increases Radiation Sensitivity of Cancer Cells.

Radiation therapy is one of the most common treatments for cancer. However, enhancing tumors' radiation sensitivity and overcoming tolerance remain a challenge. Previous studies have shown that the Ras signaling pathway directly influences tumor radiation sensitivity. Herein, we designed a series of Ras-targeting stabilized peptides, with satisfactory binding affinity (KD = 0.13 μM with HRas) and good cellular uptake. Peptide H5 inhibited downstream phosphorylation of ERK and increased radio-sensitivity in HeLa cells, resulting in significantly reduced clonogenic survival. The stabilized peptides, designed with an N-terminal nucleation strategy, acted as potential radio-sensitizers and broadened the applications of this kind of molecule. This is the first report of using stabilized peptides as radio-sensitizers, broadening the applications of this kind of molecule.

Dielectrophoresis: Measurement technologies and auxiliary sensing applications.

Dielectrophoresis (DEP), which arises from the interaction between dielectric particles and an aqueous solution in a nonuniform electric field, contributes to the manipulation of nano and microparticles in many fields, including colloid physics, analytical chemistry, molecular biology, clinical medicine, and pharmaceutics. The measurement of the DEP force could provide a more complete solution for verifying current classical DEP theories. This review reports various imaging, fluidic, optical, and mechanical approaches for measuring the DEP forces at different amplitudes and frequencies. The integration of DEP technology into sensors enables fast response, high sensitivity, precise discrimination, and label-free detection of proteins, bacteria, colloidal particles, and cells. Therefore, this review provides an in-depth overview of DEP-based fabrication and measurements. Depending on the measurement requirements, DEP manipulation can be classified into assistance and integration approaches to improve sensor performance. To this end, an overview is dedicated to developing the concept of trapping-on-sensing, improving its structure and performance, and realizing fully DEP-assisted lab-on-a-chip systems.

CARMIL1 regulates liver cancer cell proliferation by activating the ERK/mTOR pathway through the TRIM27/p53 axis

Capping protein regulatory factor and myosin 1 linker 1 is termed CARMIL1. CARMIL1 is involved in several physiological processes; it forms an actin filament network and plasma membrane-bound cellular projection tissues and positively regulates the cellular components and tissues. CARMIL1 exhibits important biological functions in cancer; nonetheless, these functions have not been completely explored. We aimed to investigate the novel functions of CARMIL1 in liver cancer, particularly in cell proliferation. The cell counting kit-8, 5-ethynyl-2′-deoxyuridine, Component A experiments, and subcutaneous tumor formation model suggest that CARMIL1 is central to the proliferation of liver cancer cells both in vivo and in vitro. We extracted CARMIL1 samples from The Cancer Genome Atlas Program and analyzed its enrichment. CARMIL1 regulated the pathway activity by affecting the expression of star molecular proteins of the extracellular signal-regulated kinase (ERK) and mammalian target of rapamycin (mTOR). Moreover, it influenced the proliferation ability of liver cancer cells. Western blotting suggested that CARMIL1 downregulation could affect ERK and mTOR phosphorylation. Results of the co-immunoprecipitation demonstrated that CARMIL1 binds to tripartite motif (TRIM)27, which in turn binds to p53. Subsequently, CARMIL1 can regulate p53 stability and promote its degradation through TRIM27. Additionally, CARMIL1 inhibition enhanced the sensitivity of liver cancer cells to sorafenib. Tumor growth was significantly inhibited in the group treated with sorafenib and CARMIL1, compared with the group treated with CARMIL1 alone. Sorafenib is a first-line targeted chemotherapeutic drug for hepatocellular carcinoma treatment. It increases the long-term survival of hepatocellular carcinoma by 44%. In this study, downregulated CARMIL1 combined with sorafenib significantly reduced the tumor volume and weight of the mouse subcutaneous tumor model, indicating the potential possibility of combining CARMIL1 with sorafenib in hepatocellular carcinoma treatment. In summary, CARMIL1 promotes liver cancer cell proliferation by regulating the TRIM27/p53 axis and activating the ERK/mTOR pathway.

ATP6V1B1 regulates ovarian cancer progression and cisplatin sensitivity through the mTOR/autophagy pathway.

Early detection and effective chemotherapy for ovarian cancer, a serious gynecological malignancy, require further progress. This study aimed to investigate the molecular mechanism of ATPase H+-Transporting V1 Subunit B1 (ATP6V1B1) in ovarian cancer development and chemoresistance. Our data show that ATP6V1B1 is upregulated in ovarian cancer and correlated with decreased progression-free survival. Gain- and loss-of-function experiments demonstrated that ATP6V1B1 promotes the proliferation, migration, and invasion of ovarian cancer cells in vitro, while ATP6V1B1 knockout inhibits tumor growth in vivo. In addition, knocking down ATP6V1B1 increases the sensitivity of ovarian cancer cells to cisplatin. Mechanistic studies showed that ATP6V1B1 regulates the activation of the mTOR/autophagy pathway. Overall, our study confirmed the oncogenic role of ATP6V1B1 in ovarian cancer and revealed that ATP6V1B1 promotes ovarian cancer progression via the mTOR/autophagy axis.

CircPDK1 competitively binds miR-4731-5p to mediate GIGYF1 expression and increase paclitaxel sensitivity in non-small cell lung cancer

ObjectiveTo investigate the action of circPDK1 in paclitaxel (PTX) resistance in non-small cell lung cancer (NSCLC).MethodscircPDK1, miR-4731-5p, and GIGYF1 levels were determined by RT-qPCR and Western blot. Cell proliferation was detected by CCK-8 and colony formation assay, apoptosis by flow cytometry, invasion by Transwell assay. The targeting relationship between miR-4731-5p and circPDK1 or GIGYF1 was confirmed by dual luciferase reporter gene and RIP assay. A xenograft tumor model was established to determine the role of circPDK1 in PTX resistance.ResultscircPDK1 was overexpressed in PTX-resistant NSCLC, and depleting circPDK1 hampered proliferation and invasion of PTX-resistant cells, activated apoptosis, and improved PTX sensitivity. circPDK1 bound to miR-4731-5p, and increasing miR-4731-5p expression salvaged the effect of circPDK1 depletion on PTX resistance. miR-4731-5p directly targeted GIGYF1, and upregulating GIGYF1 offset the promoting effect of circPDK1 knockdown on PTX sensitivity. NSCLC tumor growth was inhibited and PTX sensitivity improved when circPDK1 was suppressed.ConclusionDepleting circPDK1 promotes PTX sensitivity of NSCLC cells via miR-4731-5p/GIGYF1 axis, thereby inhibiting NSCLC pregnancy.

Characterization of alternative splicing events and prognostic signatures in gastric cancer

BackgroundAccumulating evidences indicate that the specific alternative splicing (AS) events are linked to the occurrence and prognosis of gastric cancer (GC). Nevertheless, the impact of AS is still unclear and needed to further elucidation.MethodsThe expression profile of GC and normal samples were downloaded from TCGA. AS events were achieved from SpliceSeq database. Cox regression together with LASSO analysis were employed to identify survival-associated AS events (SASEs) and calculate risk scores. PPI and pathway enrichment analysis were implemented to determine the function and pathways of these genes. Kaplan-Meier (K-M) analysis and Receiver Operating Characteristic Curves were used to evaluate the clinical significance of genes of SASEs. Q-PCR were applied to validate the hub genes on the survival prognosis in 47 GC samples. Drug sensitivity and immune cell infiltration analysis were conducted.ResultsIn total, 48 140 AS events in 10 610 genes from 361 GC and 31 normal samples were analyzed. Through univariate Cox regression, 855 SASEs in 763 genes were screened out. Further, these SASEs were analyzed by PPI and 17 hub genes were identified. Meanwhile, using Lasso and multivariate Cox regression analysis, 135 SASEs in 132 genes related to 7 AS forms were further screened and a GC prognostic model was constructed. K-M curves indicates that high-risk group has poorer prognosis. And the nomogram analysis on the basis of the multivariate Cox analysis was disclosed the interrelationships between 7 AS forms and clinical parameters in the model. Five key genes were then screened out by PPI analysis and Differential Expression Gene analysis based on TCGA and Combined-dataset, namely STAT3, RAD51B, SOCS2, POLE2 and TSR1. The expression levels of AS in STAT3, RAD51B, SOCS2, POLE2 and TSR1 were all significantly correlated with survival by qPCR verification. Nineteen drugs were sensitized to high-risk patients and eight immune cells showed significantly different infiltration between the STAD and normal groups.ConclusionsIn this research, the prognostic model constructed by SASEs can be applied to predict the prognosis of GC patients and the selected key genes are expected to become new biomarkers and therapeutical targets for GC treatment.

Baicalin enhances the chemotherapy sensitivity of oxaliplatin-resistant gastric cancer cells by activating p53-mediated ferroptosis

Gastric cancer is one of the most common malignant tumors, and chemotherapy is the main treatment for advanced gastric cancer. However, chemotherapy resistance leads to treatment failure and poor prognosis in patients with gastric cancer. Multidrug resistance (MDR) is a major challenge that needs to be overcome in chemotherapy. According to recent research, ferroptosis activation is crucial for tumor therapeutic strategies. In this work, we explored the solution to chemoresistance in gastric cancer by investigating the effects of the Chinese medicine monomer baicalin on ferroptosis. Baicalin with different concentrations was used to treat the parent HGC27 and drug-resistant HGC27/L cells of gastric cancer. Cell viability was measured by CCK8, and synergistic effects of baicalin combined with oxaliplatin were evaluated using Synergy Finder software. The effects of baicalin on organelles and cell morphology were investigated using projective electron microscopy. Iron concentration, MDA production and GSH inhibition rate were measured by colorimetry. ROS accumulation was detected by flow cytometry. The ferroptosis-related genes (IREB2, TfR, GPX4, FTH1), P53, and SLC7A11 were analysed by Western blot, and the expression differences of the above proteins between pretreatment and pretreatment of different concentrations of baicalin, were assayed in both parental HGC27 cells and Oxaliplatin-resistant HGC27/L cells. Mechanically, Baicalin disrupted iron homeostasis and inhibits antioxidant defense, resulting in iron accumulation, lipid peroxide aggregation, and specifically targeted and activated ferroptosis by upregulating the expression of tumor suppressor gene p53, thereby activating the SLC7A11/GPX4/ROS pathway mediated by it. Baicalin activates ferroptosis through multiple pathways and targets, thereby inhibiting the viability of oxaliplatin-resistant gastric cancer HGC27/L cells and enhancing the sensitivity to oxaliplatin chemotherapy.

Progressive enhanced photodynamic therapy and enhanced chemotherapy fighting against malignant tumors with sequential drug release

During the process of malignant tumor treatment, photodynamic therapy (PDT) exerts poor efficacy due to the hypoxic environment of the tumor cells, and long-time chemotherapy reduces the sensitivity of tumor cells to chemotherapy drugs due to the presence of drug-resistant proteins on the cell membranes for drug outward transportation. Therefore, we reported a nano platform based on mesoporous silica coated with polydopamine (MSN@PDA) loading PDT enhancer MnO2, photosensitizer indocyanine green (ICG) and chemotherapeutic drug doxorubicin (DOX) (designated as DMPIM) to achieve a sequential release of different drugs to enhance treatment of malignant tumors. MSN was first synthesized by a template method, then DOX was loaded into the mesoporous channels of MSN, and locked by the PDA coating. Next, ICG was modified by π–π stacking on PDA, and finally, MnO2 layer was accumulated on the surface of DOX@MSN@PDA- ICG@MnO2, achieving orthogonal loading and sequential release of different drugs. DMPIM first generated oxygen (O2) through the reaction between MnO2 and H2O2 after entering tumor cells, alleviating the hypoxic environment of tumors and enhancing the PDT effect of sequentially released ICG. Afterwards, ICG reacted with O2 in tumor tissue to produce reactive oxygen species, promoting lysosomal escape of drugs and inactivation of p-glycoprotein (p-gp) on tumor cell membranes. DOX loaded in the MSN channels exhibited a delay of approximately 8 h after ICG release to exert the enhanced chemotherapy effect. The drug delivery system achieved effective sequential release and multimodal combination therapy, which achieved ideal therapeutic effects on malignant tumors. This work offers a route to a sequential drug release for advancing the treatment of malignant tumors.

Exploration of the influence of GOLGA8B on prostate cancer progression and the resistance of castration-resistant prostate cancer to cabazitaxel

Castration-resistant prostate cancer (CRPC) represents the final stage of prostate cancer (PCa). Cabazitaxel, a taxane chemotherapy drug, is used in treating CRPC. However, patients with CRPC eventually develop resistance to cabazitaxel, and the underlying mechanism remains unclear. Here, we aimed to investigate potential genetic alterations that may play a role in CRPC resistance to cabazitaxel. Using microarray data from the GSE158494 dataset, we identified ten critical genes (CXCL8, ITGB8, CLIP4, MAP1B, WIPI1, MMP13, CXCL1, C1S, GOLGA8B, and CXCL6) associated with CRPC cell resistance to cabazitaxel. The potential function of these key genes in PCa progression was analyzed using different databases, including Gene Expression Omnibus (GEO), The Cancer Genome Atlas (TCGA), and Chinese Prostate Cancer Genome and Epigenome Atlas (CPGEA). Our findings revealed altered expression of these genes in the development of PCa. Furthermore, CXCL1 and GOLGA8B were found to influence the disease-free survival (DFS) status of patients with PCa, with GOLGA8B affecting the overall prognosis in patients with PCa. Additionally, GOLGA8B expression was associated with the infiltration of various immune cells in PCa, and it was upregulated in clinical PCa and CRPC samples. Through CCK-8 assays, we established that GOLGA8B could influence the sensitivity of CRPC cells to cabazitaxel and docetaxel. In conclusion, we identified GOLGA8B as a crucial gene that influences PCa progression and contributes to CRPC resistance to cabazitaxel.

Activated interferon response from DNA damage in multiple myeloma cells contributes to the chemotherapeutic effects of anthracyclines

IntroductionMultiple myeloma (MM) is a malignant plasma cell disease caused by abnormal proliferation of clonal plasma cells in bone marrow. Upfront identification of tumor subgroups with specific biological markers has the potential to improve biologically-driven therapy. Previously, we established a molecular classification by stratifying multiple myeloma into two subtypes with a different prognosis based on a gene module co-expressed with MCL-1 (MCL1-M).MethodsGene Ontology (GO) analysis with differentially expressed genes was performed to identify signal pathway. Drug sensitivity was analyzed using the OncoPredict algorithm. Drug sensitivity of different myeloma cell lines was detected by CCK8 and flow cytometry. RNA-seq was performed on drug-sensitive cell lines before and after adriamycin treatment. RT-qPCR was used to further verify the sequencing results. The expression of γ-H2AX and dsDNA in sensitive and resistant cell lines was detected by immunofluorescence method.ResultsIn our study, we demonstrated that MCL1-M low MM were more sensitive to anthracyclines. We treated different myeloma cell lines with doxorubicin in vitro and discovered the association of drug sensitivity with IFN signaling. Herein, we demonstrate that the doxorubicin-sensitive myeloma cell line showed significant DNA damage and up-regulated expression of genes related to the IFN response, which was not observed in drug-insensitive cell lines.DiscussionOur results suggest that the active IFN signaling pathway may serve as a marker for predicting chemotherapy sensitivity in patients with myeloma. With our MCL1-M molecular classification system, we can screen patients with a potentially good response to the interferon signaling pathway and provide individualized treatment for MM. We propose IFN-a as adjuvant therapy for patients with myeloma sensitive to anthracyclines to further improve the therapeutic effect and prolong the survival of patients.

MICAL-L2, as an estrogen-responsive gene, is involved in ER-positive breast cancer cell progression and tamoxifen sensitivity via the AKT/mTOR pathway

Endocrine treatment, particularly tamoxifen, has shown significant improvement in the prognosis of patients with estrogen receptor-positive (ER-positive) breast cancer. However, the clinical utility of this treatment is often hindered by the development of endocrine resistance. Therefore, a comprehensive understanding of the underlying mechanisms driving ER-positive breast cancer carcinogenesis and endocrine resistance is crucial to overcome this clinical challenge. In this study, we investigated the expression of MICAL-L2 in ER-positive breast cancer and its impact on patient prognosis. We observed a significant upregulation of MICAL-L2 expression in ER-positive breast cancer, which correlated with a poorer prognosis in these patients. Furthermore, we found that estrogen-ERβ signaling promoted the expression of MICAL-L2. Functionally, our study demonstrated that MICAL-L2 not only played an oncogenic role in ER-positive breast cancer tumorigenesis but also influenced the sensitivity of ER-positive breast cancer cells to tamoxifen. Mechanistically, as an estrogen-responsive gene, MICAL-L2 facilitated the activation of the AKT/mTOR signaling pathway in ER-positive breast cancer cells. Collectively, our findings suggest that MICAL-L2 could serve as a potential prognostic marker for ER-positive breast cancer and represent a promising molecular target for improving endocrine treatment and developing therapeutic approaches for this subtype of breast cancer.

Combined treatment of All-trans retinoic acid with Tamoxifen suppresses ovarian cancer.

Ovarian cancer is a malignant tumor of the female reproductive system, and its mortality rate is as high as 70%. Estrogen receptor α (ERα)-positive ovarian cancer accounted for most of all ovarian cancer patients. ERα can promote the growth and proliferation of tumors. The combined effect of All-trans retinoic acid (ATRA) and tamoxifen was obtained by the combination screening of tamoxifen and compound library by MTS. In addition, colony formation assay, flow cytometry analysis, immunofluorescence staining, quantitative real-time polymerase chain reaction (PCR), western blot, and tumor xenotransplantation models were used to further evaluate the efficacy of tamoxifen and ATRA in vitro and in vivo for ER-α-positive ovarian cancer. In our study, we found that All-trans retinoic acid (ATRA) can cooperate with tamoxifen to cause cell cycle arrest and apoptosis and inhibit ERα-positive ovarian cancer in vivo and in vitro. Further exploration of the mechanism found that ATRA can Inhibit genes related to the ERα signaling pathway, enhance the sensitivity of ERα-positive ovarian cancer cells to tamoxifen, and ascertain the effectiveness of tamoxifen and ATRA as treatments for ovarian cancer with an ERα-positive status. Combination of ATRA and tamoxifen is a new way for the treatment of ERα-positive ovarian cancer.

Circ_PPAPDC1A promotes Osimertinib resistance by sponging the miR-30a-3p/ IGF1R pathway in non-small cell lung cancer (NSCLC)

BackgroundRecent evidence has demonstrated that abnormal expression and regulation of circular RNA (circRNAs) are involved in the occurrence and development of a variety of tumors. The aim of this study was to investigate the effects of circ_PPAPDC1A in Osimertinib resistance in NSCLC.MethodsHuman circRNAs microarray analysis was conducted to identify differentially expressed (DE) circRNAs in Osimertinib-acquired resistance tissues of NSCLC. The effect of circ_PPAPDC1A on cell proliferation, invasion, migration, and apoptosis was assessed in both in vitro and in vivo. Dual-luciferase reporter assay, RT-qPCR, Western-blot, and rescue assay were employed to confirm the interaction between circ_PPAPDC1A/miR-30a-3p/IGF1R axis.ResultsThe results revealed that circ_PPAPDC1A was significantly upregulated in Osimertinib acquired resistance tissues of NSCLC. circ_PPAPDC1A reduced the sensitivity of PC9 and HCC827 cells to Osimertinib and promoted cell proliferation, invasion, migration, while inhibiting apoptosis in Osimertinib-resistant PC9/OR and HCC829/OR cells, both in vitro and in vivo. Silencing circ_PPAPDC1A partially reversed Osimertinib resistance. Additionally, circ_PPAPDC1A acted as a competing endogenous RNA (ceRNA) by targeting miR-30a-3p, and Insulin-like Growth Factor 1 Receptor (IGF1R) was identified as a functional gene for miR-30a-3p in NSCLC. Furthermore, the results confirmed that circ_PPAPDC1A/miR-30a-3p/IGF1R axis plays a role in activating the PI3K/AKT/mTOR signaling pathway in NSCLC with Osimertinib resistance.ConclusionsTherefore, for the first time we identified that circ_PPAPDC1A was significantly upregulated and exerts an oncogenic role in NSCLC with Osimertinib resistance by sponging miR-30a-3p to active IGF1R/PI3K/AKT/mTOR pathway. circ_PPAPDC1A may serve as a novel diagnostic biomarker and therapeutic target for NSCLC patients with Osimertinib resistance.Graphical

Circ-0075305 hinders gastric cancer stem cells by indirectly disrupting TCF4–β-catenin complex and downregulation of SOX9

CircRNAs are covalently closed, single-stranded RNA that form continuous loops and play a crucial role in the initiation and progression of tumors. Cancer stem cells (CSCs) are indispensable for cancer development; however, the regulation of cancer stem cell-like properties in gastric cancer (GC) and its specific mechanism remain poorly understood. We elucidate the specific role of Circ-0075305 in GC stem cell properties. Circ-0075305 associated with chemotherapy resistance was identified by sequencing GC cells. Subsequent confirmation in both GC tissues and cell lines revealed that patients with high expression of Circ-0075305 had significantly better overall survival (OS) rates than those with low expression, particularly when treated with postoperative adjuvant chemotherapy for GC. In vitro and in vivo experiments confirmed that overexpression of Circ-0075305 can effectively reduce stem cell-like properties and enhance the sensitivity of GC cells to Oxaliplatin compared with the control group. Circ-0075305 promotes RPRD1A expression by acting as a sponge for corresponding miRNAs. The addition of LF3 (a β-catenin/TCF4 interaction antagonist) confirmed that RPRD1A inhibited the formation of the TCF4–β-catenin transcription complex through competitive to β-catenin and suppressed the transcriptional activity of stem cell markers such as SOX9 via the Wnt/β-catenin signaling pathway. This leads to the downregulation of stem cell-like property-related markers in GC. This study revealed the underlying mechanisms that regulate Circ-0075305 in GCSCs and suggests that its role in reducing β-catenin signaling may serve as a potential therapeutic candidate.

CircHIF1A induces cetuximab resistance in colorectal cancer by promoting HIF1α-mediated glycometabolism alteration

Epidermal growth factor receptor (EGFR)-targeted therapy is an important treatment for RAS wild-type metastatic colorectal cancer (mCRC), but the resistance mechanism remains unclear. Here, the differential expression of circRNAs between Cetuximab sensitive and resistant cell lines was analyzed using whole-transcriptome sequencing. We identified that the expression of circHIF1A was significantly higher in LIM1215-R than in LIM1215. When treated with Cetuximab, downregulation of circHIF1A level weakened the proliferation and clonal formation ability of LIM1215-R, caused more cells to enter G0-G1 phase, and significantly reduced the basal respiration, ATP production, and maximal respiration, as well as the glycolytic capacity and glycolytic reserve. The response rate and prognosis of circHIF1A-positive patients were inferior to those of negative patients. Mechanistically, circHIF1A can upregulate the level of hypoxia-inducible factor 1 A (HIF1A) by competitively binding to miR-361-5p, inducing the overexpression of enzymes such as glucose transporter 1 (GLUT1) and lactate dehydrogenase A (LDHA). In a xenograft model, inhibition of circHIF1A expression increased the sensitivity to Cetuximab treatment. In conclusion, circHIF1A can promote HIF1α-mediated glycometabolism alteration to induce Cetuximab resistance in CRC. It has the potential to become a screening indicator for the Cetuximab beneficial population in mCRC and a new therapeutic target for enhancing treatment efficacy.

Correlation of gasdermin B staining patterns with prognosis, progression, and immune response in colorectal cancer

BackgroundPyroptosis is a type of programmed cell death mediated by the gasdermin family. Gasdermin B (GSDMB), as a member of gasdermin family, can promote the occurrence of cell pyroptosis. However, the correlations of the GSDMB expression in colorectal cancer with clinicopathological predictors, immune microenvironment, and prognosis are unclear.MethodsSpecimens from 267 colorectal cancer cases were analyzed by immunohistochemistry to determine GSDMB expression, CD3+, CD4+, and CD8+ T lymphocytes, CD20+ B lymphocytes, CD68+ macrophages, and S100A8+ immune cells. GSDMB expression in cancer cells was scored in the membrane, cytoplasm, and nucleus respectively. GSDMB+ immune cell density was calculated. Univariate and multivariate survival analyses were performed. The association of GSDMB expression with other clinicopathological variables and immune cells were also analyzed. Double immunofluorescence was used to identify the nature of GSDMB+ immune cells. Cytotoxicity assays and sensitivity assays were performed to detect the sensitivity of cells to 5-fluorouracil.ResultsMultivariate survival analysis showed that cytoplasmic GSDMB expression was an independent favorable prognostic indicator. Patients with positive cytoplasmic or nuclear GSDMB expression would benefit from 5-fluorouracil based chemotherapy. The assays in vitro showed that high GSDMB expression enhanced the sensitivity of colorectal cancer cells to 5-fluorouracil. Patients with positive membranous or nuclear GSDMB expression had more abundant S100A8+ immune cells in the tumor invasive front. Positive nuclear GSDMB expression indicated more CD68+ macrophages in the tumor microenvironment. Moreover, GSDMB+ immune cell density in the stroma was associated with a higher neutrophil percentage but a lower lymphocyte counts and monocyte percentage in peripheral blood. Furthermore, the results of double immunofluorescence showed that GSDMB co-expressed with CD68 or S100A8 in stroma cells.ConclusionThe GSDMB staining patterns are linked to its role in cancer progression, the immune microenvironment, systemic inflammatory response, chemotherapeutic efficacy, and prognosis. Colorectal cancer cells with high GSDMB expression are more sensitive to 5-fluorouracil. However, GSDMB expression in immune cells has different effects on cancer progression from that in cancer cells.

HMGN1 loss sensitizes lung cancer cells to chemotherapy

The high mobility group nucleosome binding (HMGN) family, constitutes a large family of non-histone protein family known to bind the acidic patch of the nucleosomes with various key cellular functions. Several studies have highlighted the pivotal roles of HMGNs in the pathogenic process of various cancer types. However, the roles of HMGN family in lung adenocarcinoma (LUAD) have not been fully elucidated. Herein, integrative analyses of multiple-omics data revealed that HMGNs frequently exhibit dysregulation in LUAD. Subsequent analysis of the clinical relevance of HMGN1 demonstrated its association with poor prognosis in LUAD and its potential as a diagnostic marker to differentiate LUAD from healthy controls. Additionally, functional enrichment analysis suggested that HMGN1 was mainly involved in DNA repair. To corroborate these findings, cellular experiments were conducted, confirming HMGN1’s crucial involvement in homologous recombination repair and its potential to enhance the sensitivity of LUAD cells to standard chemotherapeutic drugs. This study proposes HMGN1 as a novel prognostic biomarker and a promising target for chemotherapy in lung adenocarcinoma.

KiSS-1 Modulation by Epigenetic Agents Improves the Cisplatin Sensitivity of Lung Cancer Cells.

Epigenetic alterations my play a role in the aggressive behavior of Non-Small Cell Lung Cancer (NSCLC). Treatment with the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA, vorinostat) has been reported to interfere with the proliferative and invasive potential of NSCLC cells. In addition, the DNA methyltransferase inhibitor azacytidine (AZA, vidaza) can modulate the levels of the metastasis suppressor KiSS-1. Thus, since cisplatin is still clinically available for NSCLC therapy, the aim of this study was to evaluate drug combinations between cisplatin and SAHA as well as AZA using cisplatin-sensitive H460 and -resistant H460/Pt NSCLC cells in relation to KiSS-1 modulation. An analysis of drug interaction according to the Combination-Index values indicated a more marked synergistic effect when the exposure to SAHA or AZA preceded cisplatin treatment with respect to a simultaneous schedule. A modulation of proteins involved in apoptosis (p53, Bax) was found in both sensitive and resistant cells, and compared to the treatment with epigenetic agents alone, the combination of cisplatin and SAHA or AZA increased apoptosis induction. The epigenetic treatments, both as single agents and in combination, increased the release of KiSS-1. Finally, the exposure of cisplatin-sensitive and -resistant cells to the kisspeptin KP10 enhanced cisplatin induced cell death. The efficacy of the combination of SAHA and cisplatin was tested in vivo after subcutaneous inoculum of parental and resistant cells in immunodeficient mice. A significant tumor volume inhibition was found when mice bearing advanced tumors were treated with the combination of SAHA and cisplatin according to the best schedule identified in cellular studies. These results, together with the available literature, support that epigenetic drugs are amenable for the combination treatment of NSCLC, including patients bearing cisplatin-resistant tumors.

The Enigma of Norbormide, a Rattus-Selective Toxicant.

Norbormide (NRB) is a Rattus-selective toxicant, which was serendipitously discovered in 1964 and formerly marketed as an eco-friendly rodenticide that was deemed harmless to non-Rattus species. However, due to inconsistent efficacy and the emergence of second-generation anticoagulants, its usage declined, with registration lapsing in 2003. NRBs' lethal action in rats entails irreversible vasoconstriction of peripheral arteries, likely inducing cardiac damage: however, the precise chain of events leading to fatality and the target organs involved remain elusive. This unique contractile effect is exclusive to rat arteries and is induced solely by the endo isomers of NRB, hinting at a specific receptor involvement. Understanding NRB's mechanism of action is crucial for developing species-selective toxicants as alternatives to the broad-spectrum ones currently in use. Recent research efforts have focused on elucidating its cellular mechanisms and sites of action using novel NRB derivatives. The key findings are as follows: NRB selectively opens the rat mitochondrial permeability transition pore, which may be a factor that contributes to its lethal effect; it inhibits rat vascular KATP channels, which potentially controls its Rattus-selective vasoconstricting activity; and it possesses intracellular binding sites in both sensitive and insensitive cells, as revealed by fluorescent derivatives. These studies have led to the development of a prodrug with enhanced pharmacokinetic and toxicological profiles, which is currently undergoing registration as a novel efficacious eco-sustainable Rattus-selective toxicant. The NRB-fluorescent derivatives also show promise as non-toxic probes for intracellular organelle labelling. This review documents in more detail these developments and their implications.