Cooperatively inhibition effect of miR-143-5p and miR-145-5p in tumorigenesis of glioblastoma cells through modulating AKT signaling pathway.

Introduction: As the most common aggressive primary brain tumor, glioblastoma is inevitably a recurrent malignancy whose patients' prognosis is poor. miR-143 and miR-145, as tumor suppressor miRNAs, are downregulated through tumorigenesis of multiple human cancers, including glioblastoma. These two miRNAs regulate numerous cellular processes, such as proliferation and migration. This research was intended to explore the simultaneous replacement effect of miR-143, and miR-145 on in vitro tumorgenicity of U87 glioblastoma cells. Methods: U87 cells were cultured, and transfected with miR-143-5p and miR-145-5p. Afterward, the changes in cell viability, and apoptosis induction were determined by MTT assay and Annexin V/PI staining. The accumulation of cells at the cell cycle phases was assessed using the flow cytometry. Wound healing and colony formation assays were performed to study cell migration. qRT-PCR and western blot techniques were utilized to quantify gene expression levels. Results: Our results showed that miR-143-5p and 145-5p exogenous upregulation cooperatively diminished cell viability, and enhanced U-87 cell apoptosis by modulating Caspase-3/8/9, Bax, and Bcl-2 protein expression. The combination therapy increased accumulation of cells at the sub-G1 phase by modulating CDK1, Cyclin D1, and P53 protein expression. miR-143/145-5p significantly decreased cell migration, and reduced colony formation ability by the downregulation of c-Myc and CD44 gene expression. Furthermore, the results showed the combination therapy of these miRNAs could remarkably downregulate phosphorylated-AKT expression levels. Conclusion: In conclusion, miR-143 and miR-145 were indicated to show cooperative anti- cancer effects on glioblastoma cells via modulating AKT signaling as a new therapeutic approach.

Investigating the effect of LncRNA DLGAP1-AS2 suppression on chemosensitivity of gastric cancer to chemotherapy.

Gastric cancer, as the fifth most frequent disease and the fourth foremost cause of cancer-related death worldwide, remains a main clinical challenge due to its poor prognosis, limited treatment choices, and ability to metastasize. Combining siRNAs to suppress lncRNA with chemotherapeutic medications is a novel treatment approach that eventually increases the therapeutic efficacy of the drug while lessening its adverse effects. This study was performed with the purpose of examining the impact of inhibiting DLGAP1-AS2 expression on gastric cancer cells' drug chemosensitivity. AGS cells were cultured as the study cell line and were transfected with an optimum dose of DLGAP1-AS2 siRNA and then treated with oxaliplatin. Cell viability was examined using the MTT technique. Apoptosis and cell cycle were evaluated using Annexin V/PI staining and flow cytometry. Later, the scratch test was conducted to investigate the ability of cells to migrate, and the inhibition of the stemness of AGS cells was further investigated through the colony formation method. Finally, the qRT-PCR technique was used to assess the expression of Bax, Bcl-2, Caspase-3, p53, MMP-2, and CD44 genes. The MTT test indicated the effect of gene therapy with siRNA and oxaliplatin in combination reduced the chemotherapy drug dose to 29.92 µM and increased AGS cells' sensitivity to oxaliplatin. Also, the combination therapy caused a significant increase in apoptosis. However, it reduced the stemness feature, the rate of cell viability, proliferation, and metastasis compared to the effect of each treatment alone; the results also showed the arrest of the cell cycle in the Sub G1 phase after the combined treatment and a further reduction in the number and size of the formed colonies. Suppressing the expression of lncRNA DLGAP1-AS2 by siRNA followed by treatment with oxaliplatin can be utilized as an effective and new therapeutic technique for gastric cancer therapy.

Let-7a-3p overexpression increases chemosensitivity to carmustine and synergistically promotes autophagy and suppresses cell survival in U87MG glioblastoma cancer cells.

In terms of primary brain tumors, glioblastoma is one of the most aggressive and common brain tumors. The high resistance of glioblastoma to chemotherapy has made it vital to find alternative treatments and biological mechanisms to reduce the survival of cancer cells. Given that, the objective of the present research was to explore the potential of let-7a-3p when used in combination with carmustine in human glioblastoma cancer cells. Based on previous studies, the expression of let-7a is downregulated in the U87MG cell line. Let-7a-3p transfected into U87MG glioblastoma cells. Cell viability of the cells was assessed by MTT assay. The apoptotic induction in U87MG cancerous cells was determined through the utilization of DAPI and Annexin V/PI staining techniques. Moreover, the induction of autophagy and cell cycle arrest was evaluated by flow cytometry. Furthermore, cell migration was evaluated by the wound healing assay while colony formation assay was conducted to evaluate colony formation. Also, the expression of the relevant genes was evaluated using qRT-PCR. Transfection of let-7a-3p mimic in U87MG cells increased the expression of the miRNA and also increased the sensitivity of U87MG cells to carmustine. Let-7a-3p and carmustine induced sub-G1 and S phase cell cycle arrest, respectively. Combination treatment of let-7a-3p and carmustine synergistically increased arrested cells and induced apoptosis through regulating involved genes including P53, caspase-3, Bcl-2, and Bax. Combined treatment with let-7a-3p and carmustine also induced autophagy and increased the expression of the ATG5 and Beclin 1 (ATG6). Furthermore, let-7a-3p combined with carmustine inhibited cell migration via decreasing the expression of MMP-2. Moreover, the combination therapy decreased the ability of U87MG to form colonies through downregulating CD-44. In conclusion, our work suggests that combining let-7a-3p replacement therapy with carmustine treatment could be considered a promising strategy in treatment and can increase efficiency of glioblastoma chemotherapy.

Improvement of 5-fluorouracil chemosensitivity in colorectal cancer cells by siRNA-mediated silencing of STAT6 oncogene.

Objectives: Colorectal cancer (CRC) remains a major health concern worldwide due to its high incidence, mortality rate, and resistance to conventional treatments. The discovery of new targets for cancer therapy is essential to improve the survival of CRC patients. Here, this study aims to present a finding that identifies the STAT6 oncogene as a potent therapeutic target for CRC. Materials and Methods: HT-29 CRC cells were transfected with STAT6 siRNA and treated with 5-fluorouracil (5-FU) alone and combined. Then, to evaluate cellular proliferation and apoptosis percentage, MTT assay and annexin V/PI staining were carried out, respectively. Moreover, the migration ability of HT-29 cells was followed using a wound-healing assay, and a colony formation assay was performed to explore cell stemness features. Gene expression was quantified via qRT-PCR. Afterward, functional enrichment analysis was used to learn in-depth about the STAT6 co-expressed genes and the pathways to which they belong. Results: Our study shows that silencing STAT6 with small interfering RNA (siRNA) enhances the chemosensitivity of CRC cells to 5-FU, a commonly used chemotherapy drug, by inducing apoptosis, reducing proliferation, and inhibiting metastasis. These results suggest that combining 5-FU with STAT6-siRNA could provide a promising strategy for CRC treatment. Conclusion: Our study sheds light on the potential of STAT6 as a druggable target for CRC cancers, the findings offer hope for more effective treatments for CRC patients, especially those with advanced stages that are resistant to conventional therapies.

Interplay of miRNAs and lncRNAs in STAT3 signaling pathway in colorectal cancer progression.

In recent decades, colorectal cancer (CRC) has turned into one of the most widespread malignancies, and the incidence of this malignancy is expected to increase. Despite considerable improvements in therapeutic approaches, the prognosis, and the management of CRC face many problems. Likely, the main limitation in the successful treatment of CRC is the lack of appropriate clinical therapeutic targets. As an effective target, the signal transducer and activator of transcription 3 (STAT3) are regulated by a wide range of genes and involved in cellular processes, including cell growth, migration, invasion, immunosuppression, and angiogenesis. Aberrant regulation of STAT3 signaling leads to cellular dysfunction, diseases, and malignancies, including CRC. Consequently, targeting this signaling pathway is considered one of the therapeutic strategies used in CRC treatment. MicroRNAs (miRNAs) and long non-coding RNAs (lncRNAs) are non-coding RNA molecules with partial or no protein-coding activity that participate in gene regulation at epigenetic, transcriptional, and post-transcriptional levels and regulate multiple signaling pathways, including STAT3 signaling (especially JAK/STAT). Therefore, these regulatory molecules are suggested to be very promising targets to present new insights into overcoming the limitations of conventional therapeutic strategies. Therefore, the current review study aimed to summarize the therapeutic and diagnostic significance of miRNAs and lncRNAs and their therapeutic and diagnostic significance related to the expression and activity of STAT3 in CRC.

CD44 Suppression Improved the Chemosensitivity of HT-29 Colorectal Cancer Cells to 5-Fluorouracil and Inhibited Cell Migration.

Purpose: CD44 plays a pivotal role through tumorigenesis by regulating cancer cell metastasis, stemness, and chemosensitivity and is considered a promising therapeutic target for human cancers, including colorectal cancer (CRC). Therefore, the present research aimed to examine the simultaneous therapeutic effect of CD44 silencing and 5-fluorouracil (5-FU) on in vitro tumorigenesis of CRC cells. Methods: CD44 expression was initially evaluated in TCGA datasets and CRC tissues. Furthermore, functional analysis was performed on HT-29 CRC cells overexpressing CD44. The cells were transfected with CD44 siRNA and then treated with 5-FU. Consequently, to explore the combination therapy effect on cell viability, migration, apoptosis, and chromatin fragmentation, we performed MTT assay, scratch assay, Annexin V/PI staining and DAPI staining assays, respectively. The spheroid and colony formation assays were further employed to investigate stemness features. The gene expression at protein and mRNA levels were explored using western blotting and qPCR. Results: Our findings illustrated that CD44 was significantly overexpressed in CRC tissues compared to normal samples. The suppression of CD44 considerably promoted the chemosensitivity of HT-29 cells to 5-FU by apoptosis induction. Also, the combination therapy led to overexpression of apoptotic genes, including P53, caspase-3, and caspase-9, as well as downregulation of AKT1 expression. Furthermore, CD44 suppression, separately or combined with 5-FU, hindered stemness properties in HT-29 cells via downregulation of Sox2 and Nanog expression. Besides, the combination therapy remarkably downregulated MMPs and suppressed CRC cell migration. Conclusion: Considering its involvement in chemosensitivity to 5-FU, CD44 could be suggested as a potential target for improving the efficiency of CRC chemotherapy.

The emerging role of MicroRNA-182 in tumorigenesis; a promising therapeutic target.

A wide range of studies have indicated that microRNAs (miRNAs), a type of small single-stranded regulatory RNAs, are dysregulated in a different variety of human cancers. Therefore, they are expected to play important roles in tumorigenesis by functioning as oncogenic (oncomiRs) or tumor-suppressive miRNAs. Subsequently, their potential as diagnostic and therapeutic targets for malignancies has attracted attention in recent years. In particular, studies have revealed the aberrant expression of miR-182 through tumorigenesis and its important roles in various aspects of malignancies, including proliferation, metastasis, and chemoresistance. Accumulating reports have illustrated that miR-182, as a dual-role regulator, directly or indirectly regulates the expression of a wide range of genes and modulates the activity of various signaling pathways involved in tumor progression, such as JAK / STAT3, Wnt / ß-catenin, TGF-ß, and P13K / AKT. Therefore, considering the high therapeutic and diagnostic potential of miR-182, this review aims to point out the effects of miR-182 dysregulation on the signaling pathways involved in tumorigenesis.

Targeting Nanog expression increased Cisplatin chemosensitivity and inhibited cell migration in Gastric cancer cells.

Regardless of significant advances in cancer treatment, gastric cancer (GC) incidence rate is increasing worldwide. As one of the main transcription factors participating in stemness, Nanog plays a pivotal role in various aspects of tumorigenesis, metastasis, and chemosensitivity. Given that, the current research intended to evaluate the potential effects of Nanog suppression on the GC cell Cisplatin chemosensitivity and in vitro tumorigenesis. First, bioinformatics analysis was performed to evaluate the effect of Nanog expression on GC patients' survival. The MKN-45 human GC cells were transfected with specific siRNA targeting Nanog and/or treated with Cisplatin. Then, to study cellular viability and apoptosis, MTT assay and Annexin V/PI staining were done, respectively. Also, the scratch assay was performed to investigate cell migration, and MKN-45 cell stemness was followed using colony formation assay. Western blotting and qRT-PCR were used for gene expression analysis. The findings demonstrated that Nanog overexpression was significantly correlated with poor survival of GC patients, and siRNA-mediated Nanog silencing strongly increased MKN-45 cell sensitivity to Cisplatin through apoptosis induction. Also, Nanog suppression combined with Cisplatin resulted in the upregulation of the Caspase-3 and Bax/Bcl-2 ratio at mRNA levels and increased Caspase-3 activation. Moreover, reduced expression of Nanog, separately or combined with Cisplatin, inhibited MKN-45 cell migration by downregulating MMP2 mRNA and protein expression levels. The results also evidenced CD44 and SOX-2 downregulation aligned with a decreased rate of MKN-45 cell colony formation ability through treatments. Besides, Nanog downregulation significantly decreased MDR-1 mRNA expression. Taken together, the results of this study indicated that Nanog could be suggested as a promising target combined with Cisplatin-based GC therapies for reducing drug side effects and improving patients' outcomes.

B7H6 silencing increases chemosensitivity to dacarbazine and suppresses cell survival and migration in cutaneous melanoma.

Cutaneous melanoma (CM) is a highly metastatic cancer whose incidence rate is heightening worldwide. B7H6, as one of the co-stimulatory ligands of the B7 family, is expressed in malignant cells, involved in tumorigenesis. This study aimed to investigate the significance of B7H6 in CM cell chemosensitivity and metastatic ability. A375 CM cells were transfected with B7H6-siRNA and treated with dacarbazine individually or combined. The MTT assay to estimate half-maximal inhibitory concentration of dacarbazine and cell viability, the apoptotic induction using Annexin V/PI, cell cycle progression via flow cytometry, and wound healing assay for determining the migration ability of cells and assessing the clonogenic potential of A375 cells were executed. Functional analyses were performed to evaluate changes in A375 cells. The results illustrated that B7H6 suppression significantly increased the chemosensitivity of A375 cells to dacarbazine. Apoptosis induction by dacarbazine was enhanced after B7H6 knockdown through modulating Caspase-3, Bax, and Bcl-2 mRNA levels. Western blotting indicated enhancement of cleaved caspase-3 protein expression in treatment groups. A375 cells were arrested at the sub-G1 and S phases when using B7H6-siRNA and dacarbazine. B7H6 suppression combined with dacarbazine restrained cell migration through suppression of matrix metalloproteinase (MMP) expression, including MMP2, MMP3, and MMP9. In addition, the clonogenic ability of A375 cells was decreased by downregulating Sox2, Nanog, and CD44 mRNA levels. A visible decrement in STAT3 protein expression was observed in the combination group. Hence, our findings revealed that B7H6 knockdown with dacarbazine could be a promising treatment approach for cutaneous melanoma.

The expression pattern of Immune checkpoints after chemo/radiotherapy in the tumor microenvironment.

As a disease with the highest disease-associated burden worldwide, cancer has been the main subject of a considerable proportion of medical research in recent years, intending to find more effective therapeutic approaches with fewer side effects. Combining conventional methods with newer biologically based treatments such as immunotherapy can be a promising approach to treating different tumors. The concept of "cancer immunoediting" that occurs in the field of the tumor microenvironment (TME) is the aspect of cancer therapy that has not been at the center of attention. One group of the role players of the so-called immunoediting process are the immune checkpoint molecules that exert either co-stimulatory or co-inhibitory effects in the anti-tumor immunity of the host. It involves alterations in a wide variety of immunologic pathways. Recent studies have proven that conventional cancer therapies, such as chemotherapy, radiotherapy, or a combination of them, i.e., chemoradiotherapy, alter the "immune compartment" of the TME. The mentioned changes encompass a wide range of variations, including the changes in the density and immunologic type of the tumor-infiltrating lymphocytes (TILs) and the alterations in the expression patterns of the different immune checkpoints. These rearrangements can have either anti-tumor immunity empowering or immune attenuating sequels. Thus, recognizing the consequences of various chemo(radio)therapeutic regimens in the TME seems to be of great significance in the evolution of therapeutic approaches. Therefore, the present review intends to summarize how chemo(radio)therapy affects the TME and specifically some of the most important, well-known immune checkpoints' expressions according to the recent studies in this field.

The potential of B7-H6 as a therapeutic target in cancer immunotherapy.

Immune checkpoints are vital molecules that regulate T-cell function by activation or inhibition. Among the immune checkpoint molecules, the B7-family proteins are significantly involved in the immune escape of tumor cells. By binding to inhibitory receptors, they can suppress T-cell-mediated immunity. B7-family proteins are found at various stages of tumor microenvironment formation and promote tumorigenesis and tumor progression. B7-H6 (encoded by gene NCR3LG1) is a prominent member of the family. It has unique immunogenic properties and is involved in natural killer (NK) cell immunosurveillance by binding to the NKp30 receptor. High B7-H6 expression in certain tumor types and shortage of or low expression in healthy cells - except in cases of inflammatory or microbial stimulation - have made the protein an attractive target of research activities in recent years. The avoidance of NK-mediated B7-H6 detection is a mechanism through which tumor cells escape immune surveillance. The stimulation of tumorigenesis occurs by suppressing caspase cascade initiation and anti-apoptosis activity stimulation via the STAT3 pathway. The B7-H6-NKp30 complex on the tumor membrane activates the NK cells and releases both tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ). B7-H6 is highly expressed in a wide range of tumor cells, including glioma, hematologic malignant tumors, and breast cancer cells. Clinical examination of cancer patients indicated that the expression of B7-H6 is related to distant metastasis status and permits postoperative prognosis. Because of its unique properties, B7-H6 has a high potential be utilized as a biological marker for cancer diagnosis and prognosis, as well as a target for novel treatment options.

Nanog suppression enhanced the chemosensitivity of human non-small-cell lung cancer cells to Cisplatin and inhibited cell migration.

Lung cancer is the leading cause of cancer-associated death in the world. As one of the leading transcription factors in controlling stemness features, Nanog was shown to promote cancer progression, metastasis, and drug resistance. Considering that, this research was conducted to evaluate the effect of Nanog suppression using specific siRNA on the chemosensitivity of lung cancer cells to Cisplatin through inhibition of cell proliferation, migration, and stemness as well as apoptosis induction. Then, A549 lung cancer cells were transfected with Nanog siRNA and treated with Cisplatin individually or combined. Subsequently, to investigate cell proliferation and apoptosis induction, MTT assay and Annexin V/PI staining were performed, respectively. Also, colony formation assay was carried out to evaluate cell stemness features, and migration ability of A549 cells was followed using a wound-healing assay. Gene expression was quantified via qRT-PCR. The obtained results illustrated that siRNA-mediated Nanog suppression remarkably increased the chemosensitivity of A549 cells to Cisplatin through apoptosis induction. Consistently, Nanog suppression combined with Cisplatin led to upregulation of Caspase-3 apoptotic gene and Bax/Bcl-2 ratio. Besides, Nanog knockdown, individually or combined with Cisplatin, prevented colony formation ability of A549 cells by downregulating Sox2 and CD44 genes. It was also indicated that the combination therapy remarkably downregulated MMP9 expression and subsequently suppressed A549 cell migration. A significant reduction was also observed in c-Myc and PD-L1 gene expression levels. In conclusion, the findings of the current study demonstrated that silencing Nanog combined with Cisplatin could be a potent treatment approach for lung cancer patients.

Nanog, as a key cancer stem cell marker in tumor progression.

Cancer stem cells (CSCs) are a small population of malignant cells that induce tumor onset and development. CSCs share similar features with normal stem cells in the case of self-renewal and differentiation. They also contribute to chemoresistance and metastasis of cancer cells, leading to therapeutic failure. To identify CSCs, multiple cell surface markers have been characterized, including Nanog, which is found at high levels in different cancers. Recent studies have revealed that Nanog upregulation has a substantial association with the advanced stages and poor prognosis of malignancies, playing a pivotal role through tumorigenesis of multiple human cancers, including leukemia, liver, colorectal, prostate, ovarian, lung, head and neck, brain, pancreatic, gastric and breast cancers. Nanog through different signaling pathways, like JAK/STAT and Wnt/ß-catenin pathways, induces stemness, self-renewal, metastasis, invasiveness, and chemoresistance of cancer cells. Some of these signaling pathways are common in various types of cancers, but some have been found in one or two cancers. Therefore, this review aimed to focus on the function of Nanog in multiple cancers based on recent studies surveying the suitable approaches to target Nanog and inhibit CSCs residing in tumors to gain favorable results from cancer treatments.

Weighted Gene Co-Expression Network Analysis Combined with Machine Learning Validation to Identify Key Modules and Hub Genes Associated with SARS-CoV-2 Infection.

The coronavirus disease-2019 (COVID-19) pandemic has caused an enormous loss of lives. Various clinical trials of vaccines and drugs are being conducted worldwide; nevertheless, as of today, no effective drug exists for COVID-19. The identification of key genes and pathways in this disease may lead to finding potential drug targets and biomarkers. Here, we applied weighted gene co-expression network analysis and LIME as an explainable artificial intelligence algorithm to comprehensively characterize transcriptional changes in bronchial epithelium cells (primary human lung epithelium (NHBE) and transformed lung alveolar (A549) cells) during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Our study detected a network that significantly correlated to the pathogenicity of COVID-19 infection based on identified hub genes in each cell line separately. The novel hub gene signature that was detected in our study, including PGLYRP4 and HEPHL1, may shed light on the pathogenesis of COVID-19, holding promise for future prognostic and therapeutic approaches. The enrichment analysis of hub genes showed that the most relevant biological process and KEGG pathways were the type I interferon signaling pathway, IL-17 signaling pathway, cytokine-mediated signaling pathway, and defense response to virus categories, all of which play significant roles in restricting viral infection. Moreover, according to the drug-target network, we identified 17 novel FDA-approved candidate drugs, which could potentially be used to treat COVID-19 patients through the regulation of four hub genes of the co-expression network. In conclusion, the aforementioned hub genes might play potential roles in translational medicine and might become promising therapeutic targets. Further in vitro and in vivo experimental studies are needed to evaluate the role of these hub genes in COVID-19.

NANOG gene suppression and replacement of let-7 modulate the stemness, invasion, and apoptosis in breast cancer.

In the treatment of breast cancer (BC), as an important type of cancer in women, the specific cells, called cancer stem cells (CSCs), are the reason of failure and metastasis. So, targeting CSCs can be used as a novel strategy in cancer therapy in addition to common therapeutic strategies. According to the importance of CSCs, we tried to find a correlation between stemness and metastatic characteristics of BC cells, to address whether CSCs are a potential target for cancer therapy. Here, we evaluated the NANOG inhibition by siRNA and the increase of Let-7a levels by miRNA mimic in breast cancer cells and the effects of these changes on biologic aspects like cell apoptosis, stemness and invasion. Our results showed that the inhibition of NANOG combined with Let-7a restoration contributed to significant decrease in malignant phenotypes and stemness feature of BC cells. In conclusion, these findings showed that the combination of Let-7a miRNA mimic and Nanog siRNA could be exploited as a new treatment strategy to improve the cancer therapy outcome.

The synergy between miR-486-5p and tamoxifen causes profound cell death of tamoxifen-resistant breast cancer cells.

Breast cancer (BC) is the most common type of malignancy in women. A subset of breast cancers show resistance to endocrine-based therapies. The estrogen receptor (ER) plays a critical role in developing hormone-dependent BC. Loss of ER contributes to resistance to tamoxifen therapy and may contribute to mortality. Thus, it is crucial to overcome this problem. Here, using luciferase reporter assays, qRT-PCR, and Western blot analyses, we demonstrate that the microRNA miR-486-5p targets HMGA1 mRNA, decreasing its mRNA and protein levels in ER-positive (ER+) BC cells. Consistently, miR-486-5p is significantly downregulated, whereas HMGA1 is considerably upregulated in ER+ BC samples. Remarkably, while both miR-486-5p and tamoxifen individually cause G2/M cell cycle arrest, combination treatment synergistically causes profound cell death, specifically in tamoxifen-resistant ER+ cells but not in tamoxifen-sensitive ER+ cells. Combined treatment with miR-486-5p and tamoxifen also additively reduces cell migration, invasion, colony formation, mammary spheroid formation and a CD24-CD44+ cell population, representing decreased cancer stemness. However, these phenomena are independent of the tamoxifen responsiveness of the ER+ BC cells. Thus, miR-486-5p and tamoxifen exhibit additive and synergistic tumor-suppressive effects, most importantly causing profound cell death specifically in tamoxifen-resistant BC cells. Therefore, our work suggests that combining miR-486-5p replacement therapy with tamoxifen treatment is a promising strategy to treat endocrine therapy-resistant BC.

Cytotoxic T-Lymphocyte Antigen-4 in Colorectal Cancer: Another Therapeutic Side of Capecitabine.

Cytotoxic T lymphocyte antigen-4 (CTLA-4) is an inhibitory immune checkpoint that can be expressed in tumor-infiltrating lymphocytes and colorectal cancer (CRC) cells. This immune checkpoint can attenuate anti-tumoral immune responses and facilitate tumor growth and metastasis. Although capecitabine is an effective chemotherapeutic agent for treating CRC, its effect on the tumoral CTLA-4 expression remains unclear. In the current research, we applied the GSE110224 and GSE25070 datasets to characterize CTLA-4 expression in CRC patients. Then, we analyzed CTLA-4 expression in CRC samples, HT-29, HCT-166, and SW480 cell lines using real-time PCR. Our bioinformatic results have highlighted the overexpression of CTLA-4 in the CRC tissues compared to the adjacent non-tumoral tissues. Our in vitro studies have indicated that SW480 cells can substantially overexpress CTLA-4 compared to HT-29 and HCT 116 cells. In addition, capecitabine can remarkably downregulate the expression of CTLA-4 in SW480 cells. Collectively, capecitabine can inhibit the expression of CTLA-4 in CRC cells and might bridge the immunotherapy approaches with chemotherapy.

Interplay between MAPK/ERK signaling pathway and MicroRNAs: A crucial mechanism regulating cancer cell metabolism and tumor progression.

Mitogen-activated protein kinase (MAPK) signal transduction, as a highly conserved signaling pathway, is reported to be involved in various biological events, including metabolic reprogramming, cell proliferation, survival, and differentiation. Mutations in key molecules involved in MAPK/ERK signaling and dysregulation of this pathway are very common events in various human malignancies, which make the MAPK signaling a crucial signaling pathway participating in the regulation of glucose uptake by malignant cells and tumorigenesis. MicroRNAs (miRNAs), as small non-coding RNAs, are critical regulators of gene expression that play key roles in cancer initiation and progression. On the other hand, these small RNAs mutually regulate the MAPK signaling which is often overexpressed in the case of cancer progression; suggesting that crosstalk between miRNAs and this signaling pathway plays a pivotal role in the development of human cancers. Some miRNAs such as miR-20b, miR-34c-3p, miR-152, miR-181a, and miR-302b through inhibiting MAPK signaling, and miR-193a-3p, miR-330-3p, and miR-592 by activating this signaling pathway, play imperative roles in tumorigenesis. Therefore, in this review, we aimed to focus on the interplay between miRNAs and MAPK signaling in the various steps of tumorigenesis, including metabolic regulation, cell proliferation, apoptosis, metastasis, angiogenesis, and drug resistance.

The combination effect of Prominin1 (CD133) suppression and Oxaliplatin treatment in colorectal cancer therapy.

Colorectal cancer (CRC) is considered one of the leading types of cancer in the world. CD133, as a cancer stem cell marker, has a pivotal role in the development of drug resistance, migration, and stemness properties of CRC cells. This study was designed to check the combined effect of CD133 siRNA and Oxaliplatin on proliferation, migration, apoptosis, and stemness properties of CRC cells in the HT-29 cell line. MTT assay was performed to define the combined effect of CD133 siRNA and Oxaliplatin on the viability of HT-29 cells, and it showed that the combination of CD133 siRNA and Oxaliplatin could reduce the IC50 of this drug from 32.85 to 19.75 nmol. In order to figure out the effect of this combination therapy on CD133 expression at the gene and protein level, qRT-PCR and western blot were exploited, respectively. The results demonstrated that the silencing of CD133 could reduce the relative expression of this marker to about 0.00001 compared to the control group and reduce the protein level to 0.01. The ability of cell migration was tested by wound healing assay as well. Also, colony formation and sphere formation were conducted to assess the stemness properties in the combination group. Flow cytometry was conducted to investigate the apoptosis (15%), cell cycle (about 10% arresting in G0-G1 phase), and surface expression of CD133 in different groups (from 39.3% in the control group to 2.41 in the combination group). Finally, the expression of migration-, and stemness-associated genes were measured by qRT-PCR. We indicated that silencing of CD133 reduces the migration and stemness properties of colorectal cancerous cells. This suppression makes HT-29 cells more sensitive to Oxaliplatin and reduces the effective dose of this chemical drug. Therefore, the suppression of CD133 in combination with Oxaliplatin treatment might be a promising therapeutic approach in the treatment of colorectal cancer.

The roles of signaling pathways in SARS-CoV-2 infection; lessons learned from SARS-CoV and MERS-CoV.

The number of descriptions of emerging viruses has grown at an unprecedented rate since the beginning of the 21st century. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), is the third highly pathogenic coronavirus that has introduced itself into the human population in the current era, after SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV). Molecular and cellular studies of the pathogenesis of this novel coronavirus are still in the early stages of research; however, based on similarities of SARS-CoV-2 to other coronaviruses, it can be hypothesized that the NF-κB, cytokine regulation, ERK, and TNF-α signaling pathways are the likely causes of inflammation at the onset of COVID-19. Several drugs have been prescribed and used to alleviate the adverse effects of these inflammatory cellular signaling pathways, and these might be beneficial for developing novel therapeutic modalities against COVID-19. In this review, we briefly summarize alterations of cellular signaling pathways that are associated with coronavirus infection, particularly SARS-CoV and MERS-CoV, and tabulate the therapeutic agents that are currently approved for treating other human diseases.