Co-expression of HIF-1α, MDR1 and LAPTM4B in peripheral blood of solid tumors

P-Glycoprotein Drives Glioblastoma Survival and Chemotherapy Resistance: Potential as a Promising Liquid Biopsy Biomarker

Drug resistance is a major challenge in cancer therapy, and the expression of efflux pumps such as P-glycoprotein (P-gp, ABCB1) often correlates with poor prognosis in various tumors, including glioblastoma (GB). Considering that different roles for these proteins have been established in the biology of various tumors, this study aimed to investigate the functions of P-gp in GB-derived cells by evaluating its survival, migratory, and apoptosis-regulating capabilities, as well as its potential as a liquid biopsy biomarker. P-gp expression was diminished via siRNA to determine its exact role in GB biology. The P-gp mRNA levels were evaluated by using quantitative real-time RT-PCR. With respect to liquid biopsy, circulating cell-free RNA was extracted from plasma belonging to patients diagnosed with GB, and P-gp levels were compared with matching tumor tissues using digital PCR. P-gp silencing significantly decreased viability, increased apoptosis, and enhanced chemotherapy sensitivity in GB cells, although it did not affect migratory patterns. Finally, P-gp expression levels in circulating cell-free RNA from patients with GB matched tumor tissue, whereas healthy volunteers appeared to bear no circulating P-gp. Taken together, the results indicate that P-gp affects GB tumor biology beyond its known role in drug resistance and could integrate a broader molecular signature for future diagnosis via liquid biopsy.

Gastric Carcinoma with low ROR alpha, low E- Cadherin and High LAPTM4B Immunohistochemical Profile; is associated with unfavorable prognosis in Egyptian patients

In view of multiplicity of carcinogenic pathways of gastric carcinoma (GC), poor survival and chemotherapy resistance, more analysis of these pathways is required for prediction of prognosis and developing new therapeutic targets. Knocking down of RORα; induces tumor cell proliferation and epithelial-mesenchymal transition (EMT). LAPTM4B has been suggested to be associated with EMT which promote tumor invasion. This work aimed to investigate prognostic role of RORα, LAPTM4B, and E-Cadherin expression in GC. This retrospective immunohistochemical study assesses the expression of RORα, LAPTM4B, and E-Cadherin in 73 primary gastric carcinomas. Low RORα and high LAPTM4B expression in GC cases were associated with unfavorable prognostic factors such as positive lymph nodes, and high tumor budding. E-Cadherin heterogeneous staining was associated with poor prognostic criteria, such as diffuse type GC and high tumor budding. Low RORα, high LAPTM4B, and heterogeneous E-Cadherin were the most common immunohistochemical profile in GC cases. Low RORα expression showed poor prognostic impact on overall patient survival. In conclusion, RORα and LAPTM4B may have crucial role in GC aggressiveness. The predominance of low RORα, high LAPTM4B, and heterogeneous or negative E-Cadherin immunohistochemical profile in GC cases with unfavorable pathological parameters suggested that this profile may predict tumor behavior.

Hypoxia inducible factor-1α (HIF-1α) in breast cancer: The crosstalk with oncogenic and onco-suppressor factors in regulation of cancer hallmarks

Low oxygen level at tumor microenvironment leads to a condition, known as hypoxia that is implicated in cancer progression. Upon hypoxia, HIF-1α undergoes activation and due to its oncogenic function and interaction with other molecular pathways, promotes tumor progression. The HIF-1α role in regulating breast cancer progression is described, Overall, HIF-1α has upregulation in breast tumor and due to its tumor-promoting function, its upregulation is in favor of breast tumor progression. HIF-1α overexpression prevents apoptosis in breast tumor and it promotes cell cycle progression. Silencing HIF-1α triggers cycle arrest and decreases growth. Migration of breast tumor enhances by HIF-1α signaling and it mainly induces EMT in providing metastasis. HIF-1α upregulation stimulates drug resistance and radio-resistance in breast tumor. Furthermore, HIF-1α signaling induces immune evasion of breast cancer. Berberine and pharmacological intervention suppress HIF-1α signaling in breast tumor and regulation of HIF-1α by non-coding RNAs occurs. Furthermore, HIF-1α is a biomarker in clinic.

Gastric Carcinoma with low ROR alpha, low E- Cadherin and High LAPTM4B Immunohistochemical Profile; is associated with poor prognosis in Egyptian patients.. [DOI: 10.21203/rs.3.rs-2123133/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Background Gastric carcinoma (GC) is the tenth most prevalent cancer in both sexes in Egypt. Many pathways have been investigated regarding pathogenesis of GC, including epithelial-mesenchymal transition (EMT) pathway. In view of multiplicity of carcinogenic pathways, poor survival and chemotherapy resistance detected in GC patients, more analysis of these pathways is required for better molecular selection of patients, prediction of prognosis and developing new therapeutic targets. Down-regulation of E-Cadherin is an important EMT stage. RORα is a tumor suppressor gene, expressed in normal epithelial tissues and reduced in a variety of human cancers. Knocking down of RORα; increase cell proliferation, EMT, migration, and invasion. LAPTM4B is a protooncogene and it has been suggested to be strictly associated with EMT induction. Therefore, this work aims to investigate the role of RORα, LAPTM4B and E-Cadherin and its relationship to prognosis of GC. Methods This is a retrospective study where the standard immunohistochemical technique was done to assess the expression of RORα, LAPTM4B and E-Cadherin in 167 cases of chronic gastritis (control group) and 73 primary gastric carcinomas (51 of them have available adjacent non tumor tissue). Results Low RORα and high LAPTM4B expression in GC cases were associated with unfavorable prognostic factors such as positive lymph nodes, and high tumor budding. E-Cadherin Heterogeneous staining was associated with poor prognostic pathological criteria, such as diffuse type GC and high tumor budding. In GC, there was significant co parallel correlation between RORα and E-Cadherin expression while LAPTM4B showed inverse correlation with E-Cadherin expression. Low RORα, high LAPTM4B, and negative or heterogeneous E-Cadherin were the most common immunohistochemical profile in GC cases. Low RORα expression showed poor prognostic impact on overall patient survival. Conclusions Low RORα H-score and increased expression of LAPTM4B were significantly associated with unfavorable prognostic parameters of GC which may indicate their crucial role in tumor aggressiveness. The predominance of low RORα, high LAPTM4B and heterogeneous or negative E-Cadherin immunohistochemical profile in GC cases with unfavorable pathological parameters suggested that this profile may predict tumor behavior and this profile could be linked to EMT molecular subtype of GC

Epigenetic Regulation During Hypoxia and Its Implications in Cancer

Hypoxia is defined as a cellular stress condition caused by a decrease in oxygen below physiologically normal levels. Cells in the core of a rapidly growing solid tumor are faced with the challenge of inadequate supply of oxygen through the blood, owing to improper vasculature inside the tumor. This hypoxic microenvironment inside the tumor initiates a gene expression program that alters numerous signaling pathways, allowing the cancer cell to eventually evade adverse conditions and attain a more aggressive phenotype. A multitude of studies covering diverse aspects of gene regulation has tried to uncover the mechanisms involved in hypoxia-induced tumorigenesis. The role of epigenetics in executing widespread and dynamic changes in gene expression under hypoxia has been gaining an increasing amount of support in recent years. This chapter discusses, in detail, various epigenetic mechanisms driving the cellular response to hypoxia in cancer.

Recent Updates on Mechanisms of Resistance to 5-Fluorouracil and Reversal Strategies in Colon Cancer Treatment

5-Fluorouracil (5-FU) plus leucovorin (LV) remain as the mainstay standard adjuvant chemotherapy treatment for early stage colon cancer, and the preferred first-line option for metastatic colon cancer patients in combination with oxaliplatin in FOLFOX, or irinotecan in FOLFIRI regimens. Despite treatment success to a certain extent, the incidence of chemotherapy failure attributed to chemotherapy resistance is still reported in many patients. This resistance, which can be defined by tumor tolerance against chemotherapy, either intrinsic or acquired, is primarily driven by the dysregulation of various components in distinct pathways. In recent years, it has been established that the incidence of 5-FU resistance, akin to multidrug resistance, can be attributed to the alterations in drug transport, evasion of apoptosis, changes in the cell cycle and DNA-damage repair machinery, regulation of autophagy, epithelial-to-mesenchymal transition, cancer stem cell involvement, tumor microenvironment interactions, miRNA dysregulations, epigenetic alterations, as well as redox imbalances. Certain resistance mechanisms that are 5-FU-specific have also been ascertained to include the upregulation of thymidylate synthase, dihydropyrimidine dehydrogenase, methylenetetrahydrofolate reductase, and the downregulation of thymidine phosphorylase. Indeed, the successful modulation of these mechanisms have been the game plan of numerous studies that had employed small molecule inhibitors, plant-based small molecules, and non-coding RNA regulators to effectively reverse 5-FU resistance in colon cancer cells. It is hoped that these studies would provide fundamental knowledge to further our understanding prior developing novel drugs in the near future that would synergistically work with 5-FU to potentiate its antitumor effects and improve the patient's overall survival.

Leptin attenuates hypoxia-induced apoptosis in human periodontal ligament cells via the reactive oxygen species-hypoxia-inducible factor-1α pathway

NEW FINDINGS

What is the central question of this study? Does leptin have an effect on hypoxia-induced apoptosis in human periodontal ligament cells (hPDLCs), and what is the potential underlying mechanism? What is the main finding and its importance? Hypoxia induces cell apoptosis and leptin expression in hPDLCs through the induction of hypoxia-inducible factor-1α and accumulation of reactive oxygen species (ROS). Leptin shows feedback inhibition on hypoxia-induced ROS-mediated apoptosis in hPDLCs, suggesting a new application of leptin for hypoxic damage in periodontal diseases.

ABSTRACT

Hypoxia-induced apoptosis of human periodontal ligament cells (hPDLCs) is an important contributor to the progression of various periodontal diseases. Although leptin has been shown to protect connective tissue cells against hypoxia-induced injury, whether it might do so by attenuating hypoxia-induced apoptosis in hPDLCs remains unclear. Here, using CoCl₂ treatment, we simulated hypoxic conditions in hPDLCs and explored whether apoptosis and reactive oxygen species (ROS) levels were related to hypoxia. After small interfering RNA (siRNA) inhibition of leptin and hypoxia-inducible factor-1α (HIF-1α), the levels of apoptosis, ROS and leptin expression were measured. We showed that in CoCl₂ -treated hPDLCs, significantly higher cell apoptosis rates and ROS accumulation were observed. Cobalt chloride also increased leptin and HIF-1α expression in hPDLCs. Further investigation of the pathway demonstrated that inhibition of ROS attenuated hypoxia-induced cell apoptosis and leptin expression, whereas siRNA inhibition of leptin aggravated hypoxia-induced cell apoptosis and ROS accumulation. Hypoxia induces cell apoptosis and leptin expression in hPDLCs through the induction of ROS and HIF-1α pathways, and leptin shows feedback inhibition on ROS-mediated apoptosis in hPDLCs. These findings suggest a new application of leptin for hypoxic damage in periodontal diseases.

Diagnostic potential of hypoxia-induced genes in liquid biopsies of breast cancer patients

In tumor cells, higher expression of glucose transporter proteins (GLUT) and carbonic anhydrases (CAIX) genes is influenced by hypoxia-induced factors (HIF).Thus, we aimed to study the expression profile of these markers in sequential peripheral blood collections performed in breast cancer patients in order to verify their predictive potential in liquid biopsies. Gene expressions were analyzed by qPCR in tumor and blood samples from 125 patients and 25 healthy women. Differential expression was determined by the 2(−ΔCq) method. Expression of HIF-1α and GLUT1 in the blood of breast cancer patients is significantly higher (90–91 and 160–161 fold increased expression, respectively; p < 0.0001) than that found in healthy women. Their diagnostic power was confirmed by ROC curve. CAIX is also more expressed in breast cancer women blood, but its expression was detected only in a few samples. But none of these genes could be considered predictive markers. Therefore, evaluation of the expression of HIF-1α and GLUT1 in blood may be a useful laboratory tool to complement the diagnosis of breast cancer, in addition to being useful for follow-up of patients and of women with a family history of breast cancer.

METTL3 promotes adriamycin resistance in MCF-7 breast cancer cells by accelerating pri-microRNA-221-3p maturation in a m6A-dependent manner

Breast cancer (BC) is the most prevalent malignant neoplasm among women and is the fifth most common cause of cancer-associated death worldwide. Acquired chemoresistance driven by genetic and epigenetic alterations is a significant clinical challenge in treating BC. However, the mechanism of BC cell resistance to adriamycin (ADR) remains to be elucidated. In this study, we identified the methyltransferase-like 3/microRNA-221-3p/homeodomain-interacting protein kinase 2/Che-1 (METTL3/miR-221-3p/HIPK2/Che-1) axis as a novel signaling event that may be responsible for resistance of BC cells to ADR. A dual-luciferase reporter gene assay was employed to test the presence of miR-221-3p binding sites in the 3'UTR of HIPK2. Drug resistance was evaluated by immunoblotting multidrug resistance protein 1 (MDR1) and breast cancer resistance protein (BCRP). Cultured ADR-resistant MCF-7 cells were assayed for their half maximal inhibitory concentration (IC50) values and apoptosis using an MTT assay and Annexin V-FITC/PI-labeled flow cytometry, and the cells were then xenografted into nude mice. METTL3 knockdown was shown to reduce the expression of miR-221-3p by reducing pri-miR-221-3p m6A mRNA methylation, thereby reducing the IC50 value of ADR-resistant MCF-7 cells, reducing the expression of MDR1 and BCRP, and inducing apoptosis. Mechanistically, miR-221-3p was demonstrated to negatively regulate HIPK2 and upregulate its direct target Che-1, thus leading to enhanced drug resistance in ADR-resistant MCF-7 cells. In vitro results were reproduced in nude mice xenografted with ADR-resistant MCF-7 cells. Our work elucidates an epigenetic mechanism of acquired chemoresistance in BC, in support of the METTL3/miR-221-3p/HIPK2/Che-1 axis as a therapeutic target for the improvement of chemotherapy.

Tumorigenesis and Progression As A Consequence of Hypoxic TME：A Prospective View upon Breast Cancer Therapeutic Targets

Intratumoral hypoxia has a significant impact on the development and progression of breast cancer (BC). Rather than exerting limited regional impact, hypoxia create an aggressive macroenvironment for BC. Hypoxia-inducible factors-1(HIF-1) is extensively induced under hypoxia condition of BC, activating the transcription of multiple oncogenes. Thereinto, CD73 is the one which could be secreted into the microenvironment and is in favor of the growth, metastasis, resistance to therapies, as well as the stemness maintenance of BC. In this review, we address the significance of hypoxia/HIF-1/CD73 axis for BC, and provide a novel perspective into BC therapeutic strategies.

Mechanisms of the Epithelial-Mesenchymal Transition and Tumor Microenvironment in Helicobacter pylori-Induced Gastric Cancer

Helicobacter pylori (H. pylori) is one of the most common human pathogens, affecting half of the world’s population. Approximately 20% of the infected patients develop gastric ulcers or neoplastic changes in the gastric stroma. An infection also leads to the progression of epithelial–mesenchymal transition within gastric tissue, increasing the probability of gastric cancer development. This paper aims to review the role of H. pylori and its virulence factors in epithelial–mesenchymal transition associated with malignant transformation within the gastric stroma. The reviewed factors included: CagA (cytotoxin-associated gene A) along with induction of cancer stem-cell properties and interaction with YAP (Yes-associated protein pathway), tumor necrosis factor α-inducing protein, Lpp20 lipoprotein, Afadin protein, penicillin-binding protein 1A, microRNA-29a-3p, programmed cell death protein 4, lysosomal-associated protein transmembrane 4β, cancer-associated fibroblasts, heparin-binding epidermal growth factor (HB-EGF), matrix metalloproteinase-7 (MMP-7), and cancer stem cells (CSCs). The review summarizes the most recent findings, providing insight into potential molecular targets and new treatment strategies for gastric cancer.