Long Non-Coding RNAs as Strategic Molecules to Augment the Radiation Therapy in Esophageal Squamous Cell Carcinoma

Role of exosomes in metastasis and therapeutic resistance in esophageal cancer

Esophageal cancer (EC) has a high incidence and mortality rate and is emerging as one of the most common health problems globally. Owing to the lack of sensitive detection methods, uncontrollable rapid metastasis, and pervasive treatment resistance, EC is often diagnosed in advanced stages and is susceptible to local recurrence. Exosomes are important components of intercellular communication and the exosome-mediated crosstalk between the cancer and surrounding cells within the tumor microenvironment plays a crucial role in the metastasis, progression, and therapeutic resistance of EC. Considering the critical role of exosomes in tumor pathogenesis, this review focused on elucidating the impact of exosomes on EC metastasis and therapeutic resistance. Here, we summarized the relevant signaling pathways involved in these processes. In addition, we discussed the potential clinical applications of exosomes for the early diagnosis, prognosis, and treatment of EC.

Novel Molecular Mechanisms Underlying Tumorigenesis and Innovative Therapeutic Approaches for Cancer-Fighting

Remarkable advances have been made in cancer therapy; however, the high degree of cellular heterogeneity observed during cancer progression is the major driver in the development of resistant phenotypes upon treatment administration [...].

LINC00324 promotes cell proliferation and metastasis of esophageal squamous cell carcinoma through sponging miR-493-5p via MAPK signaling pathway

Long non-coding RNAs have been demonstrated to promote proliferation and metastasis via regulating the miRNA/mRNA regulatory axis in various malignancies. Based on our preliminary study, we investigated the mechanism of LINC00324 through miR-493-5p/MAPK1 in esophageal squamous cell carcinoma (ESCC) pathogenesis. Herein, we confirmed that LINC00324 is significantly upregulated in ESCC primary cells and esophageal squamous cell carcinoma cell line KYSE-70. Silencing of LINC00324 modulates cell proliferation markers, p21, p27, c-Myc, and Cyclin D1 and epithelial-to-mesenchymal transition markers, slug, snail, ZEB1, vimentin, ZO-1, and E-cadherin protein expression in ESCC. Through bioinformatics and dual luciferase reporter assays, we identified miR-493-5p as the direct target molecule of LINC00324. We further revealed that LINC00324 negatively regulates miR-493-5p expression in ESCC. Moreover, our multiple gain-and loss-of-functional experiments proved that a combination of miR-493-5p and LINC00324 significantly rescued ESCC cell proliferation and metastatic phenotypes. Mechanistically, LINC00324 promotes ESCC pathogenesis by acting as a competing endogenous RNA and sponges miR-493-5p activity thereby activating MAPK1 during ESCC progression. We believe that targeting LINC00324 /miR-493-5p/MAPK1 axis may provide new therapeutic avenues for ESCC.

STAT signaling as a target for intervention: from cancer inflammation and angiogenesis to non-coding RNAs modulation

As a landmark, scientific investigation in cytokine signaling and interferon-related anti-viral activity, signal transducer and activator of transcription (STAT) family of proteins was first discovered in the 1990s. Today, we know that the STAT family consists of several transcription factors which regulate various molecular and cellular processes, including proliferation, angiogenesis, and differentiation in human carcinoma. STAT family members play an active role in transducing signals from cell membrane to nucleus through intracellular signaling and thus activating gene transcription. Additionally, they are also associated with the development and progression of human cancer by facilitating inflammation, cell survival, and resistance to therapeutic responses. Accumulating evidence suggests that not all STAT proteins are associated with the progression of human malignancy; however, STAT3/5 are constitutively activated in various cancers, including multiple myeloma, lymphoma, breast cancer, prostate hepatocellular carcinoma, and non-small cell lung cancer. The present review highlights how STAT-associated events are implicated in cancer inflammation, angiogenesis and non-coding RNA (ncRNA) modulation to highlight potential intervention into carcinogenesis-related cellular processes.

Ampelopsin targets in cellular processes of cancer: Recent trends and advances

Cancer is being considered as a serious threat to human health globally due to limited availability and efficacy of therapeutics. In addition, existing chemotherapeutic drugs possess a diverse range of toxic side effects. Therefore, more research is welcomed to investigate the chemo-preventive action of plant-based metabolites. Ampelopsin (dihydromyricetin) is one among the biologically active plant-based chemicals with promising anti-cancer actions. It modulates the expression of various cellular molecules that are involved in cancer progressions. For instance, ampelopsin enhances the expression of apoptosis inducing proteins. It regulates the expression of angiogenic and metastatic proteins to inhibit tumor growth. Expression of inflammatory markers has also been found to be suppressed by ampelopsin in cancer cells. The present review article describes various anti-tumor cellular targets of ampelopsin at a single podium which will help the researchers to understand mechanistic insight of this phytochemical.

miR-590-5p: A double-edged sword in the oncogenesis process

Accumulating evidence suggests the critical role of miR-590-5p in various aspects of cellular homeostasis, including cancer. Furthermore, we and others have recently demonstrated that miRNA-590-5p acts as an oncogene in some cancers while it acts as a tumor-suppressor in others. However, the role of miR-590-5p in oncogenesis is more complex, like a double-edged sword. Thus, this systematic review introduces the concept, mechanism, and biological function of miR-590-5p to resolve this apparent paradox. We have also described the involvement of miR-590-5p in crucial cancer-hallmarks processes like proliferation, invasion, metastasis, and chemo radioresistance. Finally, we have presented the possible genes/pathways targets of miR-590-5p through bioinformatics analysis. This review may help in designing better biomarkers and therapeutic targets for cancers.

Impact of non-coding RNAs on cancer directed immune therapies: Now then and forever

Accumulating evidence demonstrates that the host genome's epigenetic modifications are essential for living organisms to adapt to extreme conditions. DNA methylation, covalent modifications of histone, and inter-association of non-coding RNAs facilitate the cellular manifestation of epigenetic changes in the genome. Out of various factors involved in the epigenetic programming of the host, non-coding RNAs (ncRNAs) such as microRNA (miRNA), long non-coding RNA (lncRNA), circular RNA, snoRNA and piRNA are new generation non-coding molecules that influence a variety of cellular processes like immunity, cellular differentiation, and tumor development. During tumor development, temporal changes in miRNA/LncRNA rheostat influence sterile inflammatory responses accompanied by the changes in the carcinogenic signaling in the host. At the cellular level, this is manifested by the up-regulation of Inflammasome and inflammatory pathways, which promotes cancer-related inflammation. Given this, we discuss the potential of lncRNAs, miRNAs, circular RNA, snoRNA and piRNA in regulating inflammation and tumor development in the host. This article is protected by copyright. All rights reserved.

A Pleiotropic Role of Long Non-Coding RNAs in the Modulation of Wnt/β-Catenin and PI3K/Akt/mTOR Signaling Pathways in Esophageal Squamous Cell Carcinoma: Implication in Chemotherapeutic Drug Response

Despite the availability of modern techniques for the treatment of esophageal squamous cell carcinoma (ESCC), tumor recurrence and metastasis are significant challenges in clinical management. Thus, ESCC possesses a poor prognosis and low five-year overall survival rate. Notably, the origin and recurrence of the cancer phenotype are under the control of complex cancer-related signaling pathways. In this review, we provide comprehensive knowledge about long non-coding RNAs (lncRNAs) related to Wnt/β-catenin and phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway in ESCC and its implications in hindering the efficacy of chemotherapeutic drugs. We observed that a pool of lncRNAs, such as HERES, TUG1, and UCA1, associated with ESCC, directly or indirectly targets various molecules of the Wnt/β-catenin pathway and facilitates the manifestation of multiple cancer phenotypes, including proliferation, metastasis, relapse, and resistance to anticancer treatment. Additionally, several lncRNAs, such as HCP5 and PTCSC1, modulate PI3K/Akt/mTOR pathways during the ESCC pathogenesis. Furthermore, a few lncRNAs, such as AFAP1-AS1 and LINC01014, block the efficiency of chemotherapeutic drugs, including cisplatin, 5-fluorouracil, paclitaxel, and gefitinib, used for ESCC treatment. Therefore, this review may help in designing a better therapeutic strategy for ESCC patients.

Circulating Long Non-Coding RNAs LINC00324 and LOC100507053 as Potential Liquid Biopsy Markers for Esophageal Squamous Cell Carcinoma: A Pilot Study

Background

Despite the availability of advanced technology to detect and treat esophageal squamous cell carcinoma (ESCC), the 5-year survival rate of ESCC patients is still meager. Recently, long non-coding RNAs (lncRNAs) have emerged as essential players in the diagnosis and prognosis of various cancers.

Objective

This pilot study focused on identifying circulating lncRNAs as liquid biopsy markers for the ESCC.

Methodology

We performed next-generation sequencing (NGS) to profile circulating lncRNAs in ESCC and healthy individuals’ blood samples. The expression of the top five upregulated and top five downregulated lncRNAs were validated through quantitative real-time PCR (qRT-PCR), including samples used for the NGS. Later, we explored the diagnostic/prognostic potential of lncRNAs and their impact on the clinicopathological parameters of patients. To unravel the molecular target and pathways of identified lncRNAs, we utilized various bioinformatics tools such as lncRnome, RAID v2.0, Starbase, miRDB, TargetScan, Gene Ontology, and KEGG pathways.

Results

Through NGS profiling, we obtained 159 upregulated, 137 downregulated, and 188 neutral lncRNAs in ESCC blood samples compared to healthy individuals. Among dysregulated lncRNAs, we observed LINC00324 significantly upregulated (2.11-fold; p-value = 0.0032) and LOC100507053 significantly downregulated (2.22-fold; p-value = 0.0001) in ESCC patients. Furthermore, we found LINC00324 and LOC100507053 could discriminate ESCC cancer patients’ from non-cancer individuals with higher accuracy of Area Under the ROC Curve (AUC) = 0.627 and 0.668, respectively. The Kaplan-Meier and log-rank analysis revealed higher expression levels of LINC00324 and lower expression levels of LOC100507053 well correlated with the poor prognosis of ESCC patients with a Hazard ratio of LINC00324 = 2.48 (95% CI: 1.055 to 5.835) and Hazard ratio of LOC100507053 = 4.75 (95% CI: 2.098 to 10.76)]. Moreover, we also observed lncRNAs expression well correlated with the age (>50 years), gender (Female), alcohol, tobacco, and hot beverages consumers. Using bioinformatics tools, we saw miR-493-5p as the direct molecular target of LINC00324 and interacted with the MAPK signaling pathway in ESCC pathogenesis.

Conclusion

This pilot study suggests that circulating LINC00324 and LOC100507053 can be used as a liquid biopsy marker of ESCC; however, multicentric studies are still warranted.

A diagnostic and prognostic value of blood-based circulating long non-coding RNAs in Thyroid, Pancreatic and Ovarian Cancer

Several studies have demonstrated the potential of circulating long non-coding RNAs (lncRNAs) as promising cancer biomarkers. Herein, we addressed the regulatory role of circulating lncRNAs and their potential value as diagnostic/prognostic markers for thyroid, pancreatic and ovarian cancers. Furthermore, we analyzed and measured the clinical implications and association of lncRNAs with sensitivity, specificity, and area under the ROC curve (AUC). Based on our meta-analysis, we found that GAS8-AS1 could discriminate thyroid cancer from non-cancer and other cancers with higher accuracy (AUC = 0.746; sensitivity = 61.70%, and specificity = 90.00%). Similarly, for ovarian cancer, lncRNA RP5-837J1.2 was found to have ideal diagnostic potential with critical clinical specifications of AUC = 0.996; sensitivity = 97.30% and specificity = 94.60%. Whereas we could not find any lncRNA having high diagnostic/prognostic efficiency in pancreatic cancer. We believe that lncRNAs mentioned above may explore clinical settings for the diagnosis and prognosis of cancer patients.

NOTCH signaling: Journey of an evolutionarily conserved pathway in driving tumor progression and its modulation as a therapeutic target

Notch signaling, an evolutionarily conserved signaling cascade, is critical for normal biological processes of cell differentiation, development, and homeostasis. Deregulation of the Notch signaling pathway has been associated with tumor progression. Thus, Notch presents as an interesting target for a variety of cancer subtypes and its signaling mechanisms have been actively explored from the therapeutic viewpoint. However, besides acting as an oncogene, Notch pathway can possess also tumor suppressive functions, being implicated in inhibition of cancer development. Given such interesting dual and dynamic role of Notch, in this review, we discuss how the evolutionarily conserved Notch signaling pathway drives hallmarks of tumor progression and how it could be targeted for a promising treatment and management of cancer. In addition, the up-to-date information on the inhibitors currently under clinical trials for Notch targets is presented along with how NOTCH inhibitors can be used in conjunction with established chemotherapy/radiotherapy regimes.

lncRNA CASC19 Contributes to Radioresistance of Nasopharyngeal Carcinoma by Promoting Autophagy via AMPK-mTOR Pathway

Nasopharyngeal carcinoma (NPC) is one of the most frequent head and neck malignant tumors and is majorly treated by radiotherapy. However, radiation resistance remains a serious obstacle to the successful treatment of NPC. The aim of this study was to discover the underlying mechanism of radioresistance and to elucidate novel genes that may play important roles in the regulation of NPC radiosensitivity. By using RNA-seq analysis of NPC cell line CNE2 and its radioresistant cell line CNE2R, lncRNA CASC19 was screened out as a candidate radioresistance marker. Both in vitro and in vivo data demonstrated that a high expression level of CASC19 was positively correlated with the radioresistance of NPC, and the radiosensitivity of NPC cells was considerably enhanced by knockdown of CASC19. The incidence of autophagy was enhanced in CNE2R in comparison with CNE2 and another NPC cell line HONE1, and silencing autophagy with LC3 siRNA (siLC3) sensitized NPC cells to irradiation. Furthermore, CASC19 siRNA (siCASC19) suppressed cellular autophagy by inhibiting the AMPK/mTOR pathway and promoted apoptosis through the PARP1 pathway. Our results revealed for the first time that lncRNA CASC19 contributed to the radioresistance of NPC by regulating autophagy. In significance, CASC19 might be a potential molecular biomarker and a new therapeutic target in NPC.