C-myc Expression Research Articles

Does immunohistochemical staining predict mobilization success in multiple myeloma patients?

BackgroundSo many risk factors for mobilization failure have been described so far. We aimed to identify the risk factors and search the possible effects of bone marrow fibrosis (BMF), CD56, c-myc, and cyclinD1 expression on mobilization. MethodsWe evaluated 189 patients with MM who were admitted for stem cell mobilization before autologous stem cell transplantation (ASCT) between 2015 and June 2021. Clinical, laboratory, treatment features, and survival outcomes were compared in patients who were successfully mobilized and who were not. ResultsMobilization failure rate was 11.1% (21) in our study group. Male gender, mobilization with only G-CSF, history of previous ASCT, lenalidomide exposure, and 2 lines of chemotherapy before stem cell mobilization were observed more commonly in mobilization failure group. There is no relationship between mobilization failure and BMF, CD56, c-myc, and cyclin D1 expression status in patients who received either only G-CSF or G-CSF+ chemotherapy for mobilization. Overall survival (OS) was not different in groups of patients who were successfully mobilized and who were not. Neutrophil engraftment was faster in patients who were transfused > 5 × 106/kg stem cells (p=0.015). ECOG performance status (p=0.004), c-myc expression (p=0.005), lenalidomide therapy before mobilization (p=0.032), and mobilization with G-CSF+chemotherapy was found to be predictive factors for OS. ConclusionEven though we could not find any predictive value of CD56, c-myc, and cyclin D1 expression on mobilization, c-myc was found to be associated with low OS. Further studies with large and homogenous study population would be more informative.

BCL11A expression worsens the prognosis of DLBCL and its co-expression with C-MYC predicts poor survival

Non-Hodgkin's lymphoma (NHL) is a significant global malignancy, with diffuse large B cell lymphoma (DLBCL) being the most prevalent subtype, accounting for 25-50% of newly diagnosed cases in China. Despite a 60% survival rate achieved with R-CHOP regiment for DLBCL, approximately 40% of patients experience relapse or develop resistance to treatment. While the oncogenic transcription factor B-cell chronic lymphocytic leukaemia/lymphoma 11A (BCL11A) has been implicated in various tumors, its specific role in DLBCL remains unclear. In this study, we conducted retrospective histomorphological and immunophenotypic analyses on paraffin sample tissues and collected fresh tissue samples for protein and mRNA analyses to investigate the relationship between BCL11A and DLBCL. Additionally, we classified DLBCL into subtypes based on cells of origin (COO) and examined the expressions of BCL11A, C-MYC, P53 and other protein expressions to better understand the factors contributing to poor clinical outcomes in DLBCL. Our findings revealed elevated BCL11A expression in DLBCL, with increased expression associated with worse prognosis and higher C-MYC expression. Patients exhibiting co-expression of C-MYC and BCL11A had significantly lower survival rates compared to those with singular expression. Furthermore, BCL11A protein expression levels demonstrated significant associations with P53 and C-MYC protein expression levels in the Germinal Center B-cell-like (GCB) subtype. These findings suggest that BCL11A may serve as a potential prognostic marker and therapeutic target for DLBCL.

Abstract C029: PM2.5-induced drug resistance in lung cancer

Abstract Long-term exposure to PM2.5 air pollution is a significant contributor to lung cancer incidence. Our previous studies have shown that such exposure promotes lung cancer progression by activating the EGFR (epidermal growth factor receptor) and AhR (aryl hydrocarbon Receptor) pathways. We observed that in lung cancer cells with EGFR mutations, prolonged PM2.5 exposure induces EGFR activation, resulting in accelerated tumor cell growth both in vitro and in vivo. This suggests that PM2.5 may play a role in the resistance to EGFR-TKI (tyrosine kinase inhibitor) therapies, raising concerns about treatment efficacy. To explore this, we exposed the EGFR-mutant lung cancer cell line to PM2.5 for 90 days. Our results revealed that long-term exposure not only reduced the therapeutic effect of EGFR-TKIs but also increased the expression of cMyc, a gene linked to poor prognosis and drug resistance. We further confirmed that PM2.5-induced EGFR-TKI resistance is driven by the AhR-cMyc pathway. AhR, activated by environmental toxins in PM2.5, increases cMyc expression, leading to drug resistance. When we administered cMyc inhibitors, the PM2.5-exposed cells regained sensitivity to EGFR-TKI therapy. These findings indicate that targeting the AhR-cMyc pathway could be a promising approach to overcome PM2.5-induced resistance in lung cancer treatment. Further research is needed to explore the broader implications of environmental pollution on cancer therapy and to develop strategies to counteract the effects of pollutants like PM2.5. Citation Format: Chi-Yuan Chen, Chieh-Wen Chan, Tong-Hong Wang. PM2.5-induced drug resistance in lung cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C029.

Histopathologic classification and immunohistochemical features of papillary renal neoplasm with potential therapeutic targets.

Papillary renal cell carcinoma (pRCC) is the second most common histological subtype of renal cell carcinoma and is considered a morphologically and molecularly heterogeneous tumor. Accurate classification and assessment of the immunohistochemical features of possible therapeutic targets are needed for precise patient care. We aimed to evaluate immunohistochemical features and possible therapeutic targets of papillary renal neoplasms. We collected 140 papillary renal neoplasms from three different hospitals and conducted immunohistochemical studies on tissue microarray slides. We performed succinate dehydrogenase B, fumarate hydratase, and transcription factor E3 immunohistochemical studies for differential diagnosis and re-classified five cases (3.6%) of papillary renal neoplasms. In addition, we conducted c-MET, p16, c-Myc, Ki-67, p53, and stimulator of interferon genes (STING) immunohistochemical studies to evaluate their pathogenesis and value for therapeutic targets. We found that c-MET expression was more common in pRCC (classic) (p = .021) among papillary renal neoplasms and Ki-67 proliferation index was higher in pRCC (not otherwise specified, NOS) compared to that of pRCC (classic) and papillary neoplasm with reverse polarity (marginal significance, p = .080). Small subsets of cases with p16 block positivity (4.5%) (pRCC [NOS] only) and c-Myc expression (7.1%) (pRCC [classic] only) were found. Also, there were some cases showing STING expression and those cases were associated with increased Ki-67 proliferation index (marginal significance, p = .063). Our findings suggested that there are subsets of pRCC with c-MET, p16, c-MYC, and STING expression and those cases could be potential candidates for targeted therapy.

Prognostic Significance of C-MYC and EGFR Overexpression in Gastrointestinal Stromal Tumors: An Immunohistochemical Study

Introduction: In addition to mutations in KIT and PDGFRA, many other genetic alterations have been described in gastrointestinal stromal tumors (GISTs), including amplifications of C-MYC and EGFR, which are often associated with increased protein expression. The main of this study was to investigate the prognostic significance of C-MYC and EGFR expression in GISTs using immunohistochemistry (IHC). Methods: We collected all GIST cases over a 16-year period. These cases were tested using antibodies against C-MYC (Leica, clone EP121) and EGFR (Leica, clone 113). C-MYC staining was assessed using the H-score method for nuclear, cytoplasmic, and combined staining. For EGFR staining (either cytoplasmic or nuclear), the intensity was graded as follows: 0 (no staining), 1 (weak staining), 2 (moderate staining), and 3 (strong staining). The percentage of positive cells was evaluated using a semiquantitative approach. Statistical analysis was performed using SPSS24. Results: A total of 37 cases were included in our study. Nuclear expression of C-MYC was observed in 43% of the cases, with a high H-score in 43%. A statistically significant association was found between a high nuclear H-score for C-MYC and mitotic rate (P=0.046), as well as a high Ki-67 proliferation rate (P=0.046). However, no statistically significant associations were identified between the nuclear H-score of C-MYC and other clinical, pathologic, or survival data. Cytoplasmic expression of C-MYC was noted in 22% of cases, but no significant correlations were found with the clinicopathological data. EGFR staining was observed in 86% of cases, with a high score of 51%. EGFR expression was significantly associated with the mitotic index (P=0.012) and Ki-67 proliferation rate (P=0.046). Conclusions: Our findings suggest that both C-MYC and EGFR may be overexpressed and/or amplified in GISTs, indicating their potential prognostic role. This could also pave the way for therapeutic strategies targeting these proteins.

Molecular alterations influencing the prognostic outcome in small pancreatic cancer (≤ 2 cm)

Abstract Purpose Pancreatic cancer (PC) is the most lethal cancer. The prognosis of small PC (tumor smaller than 20 mm) is better than that of larger PC tumors, indicating the importance of detecting early-stage PC for patient outcome. The aim of this study was to elucidate the molecular features in small PC (≤ 20 mm). Methods This study included 79 PC tumors (≤ 20 mm in pathological examination) resected between 2004 and 2022. c-Myc, Caveolin-1, Smad4, and Thrombospondin-1 were examined by immunostaining. These molecular alterations were compared in PC patients with tumor size ≤10 mm (n = 11) (14%) and 10 mm < tumor size ≤20 mm (n = 68) (86%). Mutation analyses of KRAS, PIK3CA, and BRAF were performed by pyrosequencing in 22 PCs. Results PC with 10 mm < tumor size ≤20 mm showed significantly worse overall survival and disease-free survival than PC with tumor size <10 mm (P = 0.024 and P = 0.028). Tumor c-Myc and stromal Caveolin-1 expressions were significantly increased in tumors larger than 10 mm (P = 0.02 and P = 0.04). c-Myc and Caveolin-1 expressions were associated with poor disease-free survival and overall survival. KRAS, PIK3CA, and BRAF mutation status did not differ between the two groups. Conclusions Tumor c-Myc and stromal Caveolin-1 overexpressions were detected in tumors larger than 10 mm. Their overexpressions were associated with worse prognosis even in small PC. These molecular alterations in small PC may be a clue for the detection of early-stage PC.

IGF2BP1 accelerates the aerobic glycolysis to boost its immune escape in hepatocellular carcinoma microenvironment

IntroductionEnergy metabolism abnormity emerges as a crucial factor that facilitates tumorigenesis by accelerating aerobic glycolysis. However, the function of N6-methyladenosine (m6A) on hepatocellular carcinoma (HCC) aerobic glycolysis and immune escape is still unclear. Here, this investigation was intended to elucidate the regulation of m6A ‘reader’ IGF2BP1 involved in HCC aerobic glycolysis and immune escape.MethodsThe aerobic glycolysis was tested by glucose uptake, lactate, ATP generation and ECAR. The CD8+ T cell-mediated killing effect was tested by cytotoxicity, IFN-γ and granzyme B. The molecular interaction was confirmed by luciferase reporter assay, immunoprecipitation assay and chromatin immunoprecipitation (ChIP)-PCR.ResultsElevated IGF2BP1 expression was associated with poor prognosis in HCC patients. Functionally, IGF2BP1 emerged as an oncogenic factor that accelerated HCC aerobic glycolysis (glucose uptake, lactate, ATP generation and ECAR) and oxaliplatin resistance. Meanwhile, IGF2BP1 repressed the activated CD8+ T cell-mediated killing effect (cytotoxicity, IFN-γ and granzyme B) and apoptosis of HCC cells, indicating a suppressed cytotoxic T-cell response. By recognizing and binding to the m6A-modified sites on c-Myc mRNA, IGF2BP1 enhanced the stability of c-Myc mRNA, consequently upregulating c-Myc expression. In addition, transcription factor c-Myc targeted the programmed death ligand 1 (PD-L1) promoter region to strengthen its transcription.DiscussionTaken together, this study illustrates IGF2BP1 as a potential therapeutic target in HCC, aiming to disrupt the interplay between aberrant metabolism and immune escape.

CSIG-18. YAP/TAZ TARGET GENES MAY DETERMINE THE SELF-RENEWAL AND SURVIVAL OF GLIOBLASTOMA STEM CELLS

Abstract Glioblastoma, a neoplasm arising from neuro-glial stem/progenitor cells, is the most aggressive and lethal form of brain cancer, with a median survival of 14 months. Despite intensive treatments like surgery, radiation, and chemotherapy, recurrence is inevitable, underscoring the urgent need for new treatment strategies. Progress is limited by an incomplete understanding of the biological mechanisms that drive glioblastoma formation and progression, hindering the development of effective therapies. Key molecular pathways, particularly the receptor tyrosine kinases, such as EGFR, and their effector pathways play a critical role in the initiation and maintenance of glioblastoma. Our lab’s research using patient-derived glioblastoma neurospheres and mouse models has shown that the transcriptional co-activators YAP and TAZ are overexpressed downstream of EGFR activity in EGFR-amplified or mutant glioblastoma tumors. YAP/TAZ proteins interact with the TEAD family DNA-binding proteins to promote expression of transcriptional target genes, including SOX2, C-MYC, and EGFR itself in glioblastoma, creating a positive feedback loop that enhances tumor stem cell renewal, proliferation, and survival. Furthermore, our research has demonstrated that inhibiting YAP/TAZ activity with the drug Verteporfin induces apoptosis and promotes growth arrest in patient-derived EGFR-amplified/mutant glioblastoma models. Our findings highlight YAP/TAZ-TEAD as key mediators of glioblastoma stem cell (GSC) self-renewal and survival. Ongoing experiments aim to identify tumor cell-specific YAP/TAZ-TEAD transcriptional target genes predictive of response to YAP/TAZ inhibition in GSCs within EGFR-amplified glioblastomas. Our research seeks to uncover the epigenetic basis of YAP/TAZ dependencies and to determine which genes and cellular processes are critical for tumor stem cell survival, tumor progression, and sensitivity to YAP/TAZ inhibition. These target genes could serve as biomarkers for predicting therapeutic response to YAP/TAZ inhibitors in glioblastoma.

BIOM-41. HMGB2 IS A CANDIDATE PROGNOSTIC BIOMARKER IN BOTH ADULT AND PEDIATRIC DIFFUSE GLIOMAS

Abstract Few prognostic molecular markers are common to pediatric- and adult diffuse gliomas (PDG and ADG). HMGB2 is a protein expressed in human brain development and in de-differentiated high-grade gliomas (HGG), which we have recently described as a putative prognostic and predictive biomarker in ADG, associated with proliferative activity and EIF2 signaling pathway upregulation. Additionally, we showed that HMGB2 shRNA knockdown (HMGB2-KD) reduced cell proliferation and colony formation, and radio-sensitized ADG cell lines. Aims: To assess the prognostic potential of HMGB2 in PDG and its association with stemness. METHODS 1) We singled out HMGB2 from proteomic profiles of an independent PDG cohort previously associated with EIF2 and MYCN signaling upregulation for survival analysis. 2) PDG cells SF188 were de-differentiated with substitution of DMEM by a neurobasal (NB) medium devoid of serum for stemness association studies. 3) We generated HMGB2-KD clones of PDG cell lines SF188 (grown in DMEM and NB) and KNS42 with 3 different shRNAs. RESULTS HMGB2 expression was significantly related to histological grade in PDG (grade 3 vs. grade 2 and grade 4 vs. grade 2: fold change= 8.16 and 9.39; p=0.0045 and <0.001; FDR= 0.04 and 0.0006, respectively) and survival (p=0.004, FDR=0.142 for PFS and p=0.03, FDR=0.291 for OS), in a Cox model including age and grade as covariables. Compared with cells growing in DMEM, SF188 cells growing in NB medium had a morphological change from stellate cells to round cells growing in spheres, with 2-fold increase in C-MYC and HMGB2 expression by Western analysis. HMGB2-KD resulted in >90% reduction of HMGB2 expression in SF188 and >70% in KNS42. CONCLUSION Collectively, our preliminary results suggest that HMGB2 is associated with stemness, has similar roles in PDG and ADG, and may be validated as prognostic/predictive biomarker in both adult and pediatric populations. Mechanistic studies of radiation response are underway.

CSIG-16. A CX43-WNK1-C-MYC SIGNALING AXIS DRIVES GLIOBLASTOMA CANCER STEM CELL SURVIVAL

Abstract Tumors represent a highly dynamic system that relies on coordinated signaling to drive growth and adapt to selective pressures, including those induced by anti-cancer therapies. Given the need for tumors to engage in rapid and coordinated cell-cell communication, mechanisms such as gap junction intracellular communication (GJIC) should be essential. However, the connexin proteins that make up gap junctions have traditionally been considered tumor suppressors based on the frequent loss of GJIC and lower connexin expression in tumor cells compared to non-neoplastic tissue. For this reason, connexin 43 (Cx43) has been proposed to suppress the growth of glioblastoma (GBM), the most common primary malignant brain tumor. However, recent data suggest that this tumor-suppressive effect is context dependent and that connexins can also function in a tumor-promoting role. Using next-generation sequencing techniques, we found Cx43 expressed at high levels in a panel of GBM patient-derived xenograft (PDX) CSCs and that these models rely on Cx43 for their survival and self-renewal. Mechanistically, depletion of Cx43 led to a dramatic loss of c-MYC expression through reduced phosphorylation of its upstream mediator WNK lysine-deficient protein kinase 1 (WNK1). Depletion of WNK1 phenocopied knockdown of Cx43 and reduced MYC protein and mRNA as well as tumor growth in vivo. Together, this work defines a novel signaling axis downstream of gap junction protein expression that promotes tumor growth and cancer stem cell phenotypes in GBM. Due to the difficulty in targeting both Cx43 and MYC, the identification of intermediate targetable signaling nodes may lead to improved therapies for patients with GBM.

Anthrax lethal toxin exerts potent metabolic inhibition of the cardiovascular system.

Bacillus anthracis causes anthrax through a combination of bacterial infection and toxemia. As a major virulence factor of B. anthracis, anthrax lethal toxin (LT) is a zinc-dependent metalloproteinase, exerting its cytotoxicity through proteolytic cleavage of the mitogen-activated protein kinase kinases, thereby shutting down the MAPK pathways. Anthrax lethal toxin induces host lethality mostly by targeting the cardiovascular system. Although the enzymatic activity and the molecular targets of LT have long been known, the detailed mechanisms underlying cellular/tissue/organ toxicity are still poorly understood. In this work, we sought to investigate the mechanism of LT-induced cellular damage in the cardiovascular system. We demonstrate for the first time that anthrax lethal toxin has potent inhibitory effects on the central metabolism of cardiomyocytes and endothelial cells. This is likely due to the observed downregulating of c-Myc expression through the toxin-induced inhibition of the ERK pathway. Since c-Myc is a master transcription factor controlling the expression of many rate-limiting metabolic enzymes in glycolysis and the tricarboxylic acid cycle, LT's downregulation of c-Myc may lead to the observed bioenergetic collapse, particularly, in cardiomyocytes. Since cardiac cell contraction requires continuous production of large amounts of ATP, potent inhibition of the bioenergetics of cardiomyocytes would be incompatible with life. Thus, LT-induced lethality through targeting cardiomyocytes and endothelial cells appears to be a consequence of a bioenergetic collapse, likely due to the toxin's potent inhibitory activity on the MEK-ERK-c-Myc-metabolic/bioenergetic axis within these target cells of cardiovascular system.IMPORTANCEAnthrax lethal toxin (LT) is a major virulence factor of Bacillus anthracis, the causative pathogen of anthrax disease. Anthrax lethal toxin is a metalloproteinase that cleaves and inactivates MEKs, thereby shutting down MAPK pathways, leading to host mortality primarily through targeting of the cardiovascular system. However, the detailed mechanisms underlying the toxin's cellular and tissue toxicity are still poorly understood. Here, we found that anthrax lethal toxin has potent inhibitory activity on glycolysis and oxidative phosphorylation of cardiomyocytes and endothelial cells. These effects appear to be the consequence of downregulation of c-Myc, a master transcription factor that controls many rate-limiting enzymes of glycolysis and the tricarboxylic acid cycle. With the high demand on energy for cardiac contraction, the potent inhibition of cardiomyocyte metabolism by LT would be incompatible with life. This work provides critical insights into why the cardiovascular system is the major in vivo target of LT-induced lethality.

Increased c-MYC Expression Associated with Active IGH Locus Rearrangement: An Emerging Role for c-MYC in Chronic Lymphocytic Leukemia

This review examines the pivotal role of c-MYC in Chronic Lymphocytic Leukemia (CLL), focusing on how its overexpression leads to increased genetic instability, thereby accelerating disease progression. MYC, a major oncogene, encodes a transcription factor that regulates essential cellular processes, including cell cycle control, proliferation, and apoptosis. In CLL cases enriched with unmutated immunoglobulin heavy chain variable (IGHV) genes, MYC is significantly overexpressed and associated with active rearrangements in the IGH immunoglobulin heavy chain locus. This overexpression results in substantial DNA damage, including double-strand breaks, chromosomal translocations, and an increase in abnormal repair events. Consequently, c-MYC plays a dual role in CLL: it promotes aggressive cell proliferation while concurrently driving genomic instability through its involvement in genetic recombination. This dynamic contributes not only to CLL progression but also to the overall aggressiveness of the disease. Additionally, the review suggests that c-MYC’s influence on genetic rearrangements makes it an attractive target for therapeutic strategies aimed at mitigating CLL malignancy. These findings underscore c-MYC’s critical importance in advancing CLL progression, highlighting the need for further research to explore its potential as a target in future treatment approaches.

GdX inhibits the occurrence and progression of breast cancer by negatively modulating the activity of STAT3

ABSTRACT Aim To elucidate the biological functionality and regulatory mechanisms of GdX in breast cancer (BC). Methods The examination of GdX expression in human BC tissues and cell lines was conducted through immunohistochemical (IHC) and Western blot. Cell proliferation capacity was assessed via the CCK-8 and colony formation assay, while cell migration was determined through the wound healing assay. The expression levels of BCL-XL, Cyclin D1, and C-myc gene were quantified using RT-qPCR and Western blot. In vivo tumor growth was evaluated in nude mice xenografted with MDA-MB-231 cells overexpressing GdX, and a mouse model with GdX-deficient BC was established to observe the impact of GdX on BC formation and metastasis. Dual-luciferase reporter assay and immunofluorescence were employed to confirm the interaction between GdX and STAT3. Western blot was employed to validate the influence of GdX overexpression on the phosphorylation process of STAT3. Results GdX exhibited low expression in the cancer tissues of BC patients and cell lines. MDA-MB-231 and MCF-7 cells overexpressing GdX displayed a notable reduction in proliferation and diminished migratory capabilities, accompanied by downregulated mRNA and protein expression of BCL-XL, Cyclin D1, and C-myc. In the xenograft mouse model, heightened GdX expression correlated with a decelerated in vivo tumor growth. Furthermore, in mice deteleing GdX, both the quantity and weight of tumors increased, along with evident pulmonary metastasis. Mechanistically, STAT3 emerged as a downstream target gene of GdX. Conclusions GdX exerts its inhibitory effects on the initiation and progression of BC by negatively modulating the phosphorylation of STAT3.

Discovery and optimization of novel 4-morpholinothieno[3,2-d]pyrimidine derivatives as potent BET inhibitors for cancer therapy

The identification of structurally novel and potently active BET inhibitors represents a significant advancement in the field of anticancer therapeutics. In the present investigation, leveraging the outcomes of previous screening endeavors, we successfully optimized and synthesized a novel series of bromodomain and extra-terminal (BET) inhibitors with a 4-morpholinothieno[3,2-d]pyrimidine structure. Among the synthesized compounds, compound 6c emerged as a promising candidate, exhibiting exceptional inhibitory activities against various BET isoform proteins, with IC50 values ranging from 3.3 to 42.0 nM. In cellular assays, compound 6c demonstrated robust antiproliferative effects in SU-DHL-4 cells, achieving an IC50 value of 8.6 ± 3.3 nM. Further mechanistic studies revealed that compound 6c effectively decreased the expression of c-Myc, a critical oncogenic driver regulated by the BET protein, and induced cell cycle arrest at the G1 phase, as well as cell apoptosis, in a dose-dependent manner. Moreover, in-silico prediction of the physiochemical and pharmacokinetic properties clarified that compound 6c has acceptable drug-like profiles. Taken these findings together, compound 6c represents a novel and potent BET inhibitor, thus positioning it as a promising candidate for subsequent pre-clinical evaluations in the realm of cancer therapy.

Association of glutaminase expression with immune-suppressive tumor microenvironment, clinicopathologic features, and clinical outcomes in endometrial cancer

ObjectiveIncreased glutamine metabolism by cancer cells via upregulation of the drug-targetable enzyme glutaminase may contribute to an immune-suppressive tumor microenvironment. Inhibiting glutamine metabolism can not only suppress tumor growth, but...

Unite and Conquer: Association of Two G-Quadruplex Aptamers Provides Antiproliferative and Antimigration Activity for Cells from High-Grade Glioma Patients

Background: High-grade gliomas remain a virtually incurable form of brain cancer. Current therapies are unable to completely eradicate the tumor, and the tumor cells that survive chemotherapy or radiation therapy often become more aggressive and resistant to further treatment, leading to inevitable relapses. While the antiproliferative effects of new therapeutic molecules are typically the primary focus of research, less attention is given to their influence on tumor cell migratory activity, which can play a significant role in recurrence. A potential solution may lie in the synergistic effects of multiple drugs on the tumor. Objectives: In this study, we investigated the effect of combined exposure to bi-(AID-1-T), an anti-proliferative aptamer, and its analog bi-(AID-1-C), on the migratory activity of human GBM cells. Results: We examined the effects of various sequences of adding bi-(AID-1-T) and bi-(AID-1-C) on five human GBM cell cultures. Our findings indicate that certain sequences significantly reduced the ability of tumor cells to migrate and proliferate. Additionally, the expression of Nestin, PARP1, L1CAM, Caveolin-1, and c-Myc was downregulated in human GBM cells that survived exposure, suggesting that the treatment had a persistent antitumor effect on these cells.

Cisplatin-resistance and aggressiveness are enhanced by a highly stable endothelin-converting enzyme-1c in lung cancer cells

BackgroundLung cancer constitutes the leading cause of cancer mortality. High levels of endothelin-1 (ET-1), its cognate receptor ETAR and its activating enzyme, the endothelin-converting enzyme-1 (ECE-1), have been reported in several cancer types, including lung cancer. ECE-1 comprises four isoforms, which only differ in their cytoplasmic N-terminus. Protein kinase CK2 phosphorylates the N-terminus of isoform ECE-1c, increasing its stability and leading to enhanced invasiveness in glioblastoma and colorectal cancer cells, which is believed to be mediated by the amino acid residue Lys-6, a conserved putative ubiquitination site neighboring the CK2-phosphorylated residues Ser-18 and Ser-20. Whether Lys-6 is linked to the acquisition of a cancer stem cell (CSC)-like phenotype and aggressiveness in human non–small cell lung cancer (NSCLC) cells has not been studied.MethodsIn order to establish the role of Lys-6 in the stability of ECE-1c and its involvement in lung cancer aggressiveness, we mutated this residue to a non-ubiquitinable arginine and constitutively expressed the wild-type (ECE-1cWT) and mutant (ECE-1cK6R) proteins in A549 and H1299 human NSCLC cells by lentiviral transduction. We determined the protein stability of these clones alone or in the presence of the CK2 inhibitor silmitasertib, compared to ECE-1cWT and mock-transduced cells. In addition, the concentration of secreted ET-1 in the growth media was determined by ELISA. Expression of stemness genes were determined by Western blot and RT-qPCR. Chemoresistance to cisplatin was studied by MTS viability assay. Migration and invasion were measured through transwell and Matrigel assays, respectively, and the side-population was determined using flow cytometry.ResultsECE-1cK6R displayed higher stability in NSCLC cells compared to ECE-1cWT-expressing cells, but ET-1 secreted levels showed no difference up to 48 h. Most importantly, ECE-1cK6R promoted expression of the stemness genes c-Myc, Sox-2, Oct-4, CD44 and CD133, which enhance cellular self-renewal capability. Also, the ECE-1cK6R-expressing cells showed higher cisplatin chemoresistance, correlating with an augmented side-population abundance due to the increased expression of the ABCG2 efflux pump. Finally, the ECE-1cK6R-expressing cells showed enhanced invasiveness, which correlated with the regulated expression of known EMT markers.ConclusionsOur findings suggest an important role of ECE-1c in lung cancer. ECE-1c is key in a non-canonical ET-1-independent mechanism which triggers a CSC-like phenotype, leading to enhanced lung cancer aggressiveness. Underlying this mechanism, ECE-1c is stabilized upon phosphorylation by CK2, which is upregulated in many cancers. Thus, phospho-ECE-1c may be considered as a novel prognostic biomarker of recurrence, as well as the CK2 inhibitor silmitasertib as a potential therapy for lung cancer patients.

Bile acid conjugated chitosan nanoparticles promote the proliferation and epithelial-mesenchymal transition of hepatocellular carcinoma by regulating the PI3K/Akt/mTOR pathway

Bile acids have been known to play significant roles at certain physiological levels in gastrointestinal metabolism. Yet, they are known to be carcinogenic and aid in tumor progression in most cases, although the roles remain uncertain. Hence, we tested the cytotoxic potential of cholic acid (CA) loaded chitosan nanoparticles (CNPs) on Hep3B cells. The physicochemical properties of the CNPs synthesized with CA load (CA-CNPs) were determined using standard techniques such as ultraviolet–visible spectrophotometry (UV–Vis), fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), dynamic light scattering (DLS) and transmission electron microscopy (TEM). The characteristic peak for chitosan nanoparticles were observed for plain CNPs (pCNPs) and CA-CNPs at around 300 nm as per UV–Vis analysis. FTIR analysis indicated the possible trapping of CA onto CNPs as certain peaks were retained and some peaks were shifted. XRD analysis determined that the peaks representing CA and pCNPs were collectively obtained in CA-CNPs. As per DLS analysis, the particle size, PDI and ζ-potential of the CA-CNPs were 259 nm, 0.284 and 30.4 mV. Further, the CA-CNPs were non-cytotoxic on Hep3B cells at the maximum tested concentration of 500 μg/mL. The viability at 500 μg/mL of CA-CNPs was two-fold higher than 500 μg/mL of pCNPs. Also, the pCNPs were not hemolytic and therefore could not have played a role in the increase of viability after treatment with CA-CNPs, which indicates that CA posed a major role in increased viability of Hep3B cells. As per quantitative PCR (qPCR), the upregulated gene expressions of PI3K, Akt, mTORC2, cMyc, Fibronectin, hVPS34, Slug and ZEB1 and the downregulated expression of the tumor suppressor PTEN indicates that PI3K/Akt/mTOR pathway mediated the induction of epithelial-to-mesenchymal transition (EMT) in response to CA-CNPs treatment on Hep3B cells.

WDR20 prevents hepatocellular carcinoma senescence by orchestrating the simultaneous USP12/46-mediated deubiquitination of c-Myc

The dysfunction of the ubiquitin-proteasome system (UPS) facilitates the malignant progression of hepatocellular carcinoma (HCC). While targeting the UPS for HCC therapy has been proposed, identifying effective targets has been challenging. In this study, we conducted a focused screen of siRNA libraries targeting UPS-related WD40 repeat (WDR) proteins and found that silencing WDR20, a deubiquitinating enzyme activating factor, selectively inhibited the proliferation of HCC cells without affecting normal hepatocytes. Moreover, the downregulation of WDR20 expression induced HCC cellular senescence and suppressed tumor progression in xenograft, sleeping beauty transposon/transposase, and hydrodynamic tail vein injection-induced HCC models, and Alb-Cre+/MYC+ HCC transgenic mouse models. Mechanistically, we found that WDR20 silencing disturbed the protein stability of c-Myc, orchestrating the simultaneous USP12/46-mediated deubiquitination of c-Myc, thereby promoting the transcriptional activation of CDKN1A. Further investigation revealed a positive coexpression of WDR20 and c-Myc in a tissue microarray with 88 HCC clinical samples. By employing three patient-derived organoids from individuals with HCC, we have validated the decrease in c-Myc expression and the significant induction of senescence and growth inhibition following silencing of WDR20. This study not only uncovers the biological function of WDR20 and elucidates the molecular mechanism underlying its negative regulation of HCC cellular senescence but also highlight the potential of WDR20 as a promising target for HCC therapy.

The potential role of Circular RNA New biomarkers for the prognosis of hepatocellular carcinoma

Abstract Introduction/Objective Hepatocellular carcinoma (HCC) is the most commonly diagnosed cancer with related deaths worldwide. The non-coding RNAs as the functions of circRNAs in tumor progression have attracted great attention to the clinicopathological characteristics of HCC. Methods/Case Report The present study was conducted to investigate and evaluate the expression level of hsa_circ_2124, and hsa_circ_4018 downstream target gene pathways related to clinico-pathological parameters of HCC. Cell proliferation was examined by West-1 assay and protein expression levels by using western blotting analysis. Results (if a Case Study enter NA) The hsa_circ_2124 expression level was up-regulated in HepG2 and Hep3B cells, respectively compared to normal liver cells. Furthermore, hsa_circ_4018 was down-regulated in two HCC cell lines compared to the normal cell line (LO2 cells), demonstrating the heterogeneity characteristics of the circRNA expressions in different HCC cell lines. Our data showed a significant inhibition of hsa_circ_4018 in HCC cell lines which in turn inhibited cell proliferation and migration. Besides, there is an inhibition in cell proliferation after hsa_circ_2124 knockdown in the tested cell lines. In addition, our data reported that the Knockdown of hsa_circ_2124 reduced the expression of ERK, c-Myc, and β-catenin expression in Hep-G2 cells. Furthermore, hsa_circ_4018 showed significant inhibition in β-catenin and c-Myc expression levels in Hep3B cells compared to the control. The knockdown of hsa_circ_2124 induced G1-phase arrest in HepG2 cells compared to control, suggesting the role of hsa_circ_2124 in the inhibition of HCC progression. Conclusion All in all, our data revealed that hsa_circ_2124 or hsa_circ_4018 plays a role in the regulation of MAPK and Wnt/β-catenin signaling pathways, which might be potential therapeutic biomarkers for HCC.