Decoding Insulin-Like Growth Factor Signaling Pathway From a Non-coding RNAs Perspective: A Step Towards Precision Oncology in Breast Cancer

A Novel Epigenetic Strategy to Concurrently Block Immune Checkpoints PD-1/PD-L1 and CD155/TIGIT in Hepatocellular Carcinoma

Tumor microenvironment is an intricate web of stromal and immune cells creating an immune suppressive cordon around the tumor. In hepatocellular carcinoma (HCC), Tumor microenvironment is a formidable barrier towards novel immune therapeutic approaches recently evading the oncology field. In this study, the main aim was to identify the intricate immune evasion tactics mediated by HCC cells and to study the epigenetic modulation of the immune checkpoints; Programmed death-1 (PD-1)/ Programmed death-Ligand 1 (PD-L1) and T cell immunoreceptor with Ig and ITIM domains (TIGIT)/Cluster of Differentiation 155 (CD155) at the tumor-immune synapse. Thus, liver tissues, PBMCs and sera were collected from Hepatitis C Virus (HCV), HCC as well as healthy individuals. Screening was performed to PD-L1/PD-1 and CD155/TIGIT axes in HCC patients. PDL1, CD155, PD-1 and TIGIT were found to be significantly upregulated in liver tissues and peripheral blood mononuclear cells (PBMCs) of HCC patients. An array of long non-coding RNAs (lncRNAs) and microRNAs validated to regulate such immune checkpoints were screened. The lncRNAs; CCAT-1, H19, and MALAT-1 were all significantly upregulated in the sera, PBMCs, and tissues of HCC patients as compared to HCV patients and healthy controls. However, miR-944-5p, miR-105-5p, miR-486-5p, miR-506-5p, and miR-30a-5p were downregulated in the sera and liver tissues of HCC patients. On the tumor cell side, knocking down of lncRNAs-CCAT-1, MALAT-1, or H19-markedly repressed the co-expression of PD-L1 and CD155 and accordingly induced the cytotoxicity of co-cultured primary immune cells. On the immune side, ectopic expression of the under-expressed microRNAs; miR-486-5p, miR-506-5p, and miR-30a-5p significantly decreased the transcript levels of PD-1 in PBMCs with no effect on TIGIT. On the other hand, ectopic expression of miR-944-5p and miR-105-5p in PBMCs dramatically reduced the co-expression of PD-1 and TIGIT. Finally, all studied miRNAs enhanced the cytotoxic effects of PBMCs against Huh7 cells. However, miR-105-5p showed the highest augmentation for PBMCs cytotoxicity against HCC cells. In conclusion, this study highlights a novel co-targeting strategy using miR-105-5p mimics, MALAT-1, CCAT-1 and H19 siRNAs to efficiently hampers the immune checkpoints; PD-L1/PD-1 and CD155/TIGIT immune evasion properties in HCC.

Puzzling out the role of MIAT LncRNA in hepatocellular carcinoma

A non-negligible part of our DNA has been proven to be transcribed into non-protein coding RNA and its intricate involvement in several physiological processes has been highly evidenced. The significant biological role of non-coding RNAs (ncRNAs), including long non-coding RNAs (lncRNAs) has been variously reported. In the current review, the authors highlight the multifaceted role of myocardial infarction-associated transcript (MIAT), a well-known lncRNA, in hepatocellular carcinoma (HCC). Since its discovery, MIAT has been described as a regulator of carcinogenesis in several malignant tumors and its overexpression predicts poor prognosis in most of them. At the molecular level, MIAT is closely linked to the initiation of metastasis, invasion, cellular migration, and proliferation, as evidenced by several in-vitro and in-vivo models. Thus, MIAT is considered a possible theranostic agent and therapeutic target in several malignancies. In this review, the authors provide a comprehensive overview of the underlying molecular mechanisms of MIAT in terms of its downstream target genes, interaction with other classes of ncRNAs, and potential clinical implications as a diagnostic and/or prognostic biomarker in HCC.

MIAT LncRNA: A multifunctional key player in non-oncological pathological conditions

The discovery of non-coding RNAs (ncRNAs) has unveiled a wide range of transcripts that do not encode proteins but play key roles in several cellular and molecular processes. Long noncoding RNAs (lncRNAs) are specific class of ncRNAs that are longer than 200 nucleotides and have gained significant attention due to their diverse mechanisms of action and potential involvement in various pathological conditions. In the current review, the authors focus on the role of lncRNAs, specifically highlighting the Myocardial Infarction Associated Transcript (MIAT), in non-oncological context. MIAT is a nuclear lncRNA that has been directly linked to myocardial infarction and is reported to control post-transcriptional processes as a competitive endogenous RNA (ceRNA) molecule. It interacts with microRNAs (miRNAs), thereby limiting the translation and expression of their respective target messenger RNA (mRNA) and regulating protein expression. Yet, MIAT has been implicated in other numerous pathological conditions such as other cardiovascular diseases, autoimmune disease, neurodegenerative diseases, metabolic diseases, and many others. In this review, the authors emphasize that MIAT exhibits distinct expression patterns and functions across different pathological conditions and is emerging as potential diagnostic, prognostic, and therapeutic agent. Additionally, the authors highlight the regulatory role of MIAT and shed light on the involvement of lncRNAs and specifically MIAT in various non-oncological pathological conditions.

Harnessing the supremacy of MEG3 LncRNA to defeat gastrointestinal malignancies

Evidence suggests that long non-coding RNAs (lncRNAs) play a pivotal role in the carcinogenesis and progression of various human malignancies including gastrointestinal malignancies. This comprehensive review reports the functions and mechanisms of the lncRNA maternally expressed gene 3 (MEG3) involved in gastrointestinal malignancies. It summarizes its roles in mediating the regulation of cellular proliferation, apoptosis, migration, invasiveness, epithelial-to-mesenchymal transition, and drug resistance in several gastrointestinal cancers such as colorectal cancer, gall bladder cancer, pancreatic cancer, gastric cancer, esophageal cancer, cholangiocarcinoma, gastrointestinal stromal tumors and most importantly, hepatocellular carcinoma. In addition, the authors briefly highlight its implicated mechanistic role and interactions with different non-coding RNAs and oncogenic signaling cascades. This review presents the rationale for developing non coding RNA-based anticancer therapy via harnessing the power of MEG3 in gastrointestinal malignancies.

Involvement of CircRNAs in regulating The "New Generation of Cancer Hallmarks": A Special Depiction on Hepatocellular Carcinoma

The concept of 'Hallmarks of Cancer' is an approach of reducing the enormous complexity of cancer to a set of guiding principles. As the underlying mechanism of cancer are portrayed, we find that we gain insight and additional aspects of the disease arise. The understanding of the tumor microenvironment (TME) brought a new dimension and led to the discovery of novel hallmarks such as senescent cells, non-mutational epigenetic reprogramming, polymorphic microbiomes and unlocked phenotypic plasticity. Circular RNAs (circRNAs) are single-stranded, covalently closed RNA molecules that are ubiquitous across all species. Recent studies on the circRNAs have highlighted their crucial function in regulating the formation of human malignancies through a range of biological processes. The primary goal of this review is to clarify the role of circRNAs in the most common form of liver cancer, hepatocellular carcinoma (HCC). This review also addressed the topic of how circRNAs affect HCC hallmarks, including the new generation hallmarks. Finally, the enormous applications that these rapidly expanding ncRNA molecules serve in the functional and molecular development of effective HCC diagnostic biomarkers and therapeutic targets.

Role of Hydrogen Sulfide in Oncological and Non-Oncological Disorders and Its Regulation by Non-Coding RNAs: A Comprehensive Review

Recently, myriad studies have defined the versatile abilities of gasotransmitters and their synthesizing enzymes to play a "Maestro" role in orchestrating several oncological and non-oncological circuits and, thus, nominated them as possible therapeutic targets. Although a significant amount of work has been conducted on the role of nitric oxide (NO) and carbon monoxide (CO) and their inter-relationship in the field of oncology, research about hydrogen sulfide (H2S) remains in its infancy. Recently, non-coding RNAs (ncRNAs) have been reported to play a dominating role in the regulation of the endogenous machinery system of H2S in several pathological contexts. A growing list of microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) are leading the way as upstream regulators for H2S biosynthesis in different mammalian cells during the development and progression of human diseases; therefore, their targeting can be of great therapeutic benefit. In the current review, the authors shed the light onto the biosynthetic pathways of H2S and their regulation by miRNAs and lncRNAs in various oncological and non-oncological disorders.

Pharmacogenomic and epigenomic approaches to untangle the enigma of IL-10 blockade in oncology

The host immune system status remains an unresolved mystery among several malignancies. An immune-compromised state or smart immune-surveillance tactics orchestrated by cancer cells are the primary cause of cancer invasion and metastasis. Taking a closer look at the tumour-immune microenvironment, a complex network and crosstalk between infiltrating immune cells and cancer cells mediated by cytokines, chemokines, exosomal mediators and shed ligands are present. Cytokines such as interleukins can influence all components of the tumour microenvironment (TME), consequently promoting or suppressing tumour invasion based on their secreting source. Interleukin-10 (IL-10) is an interlocked cytokine that has been associated with several types of malignancies and proved to have paradoxical effects. IL-10 has multiple functions on cellular and non-cellular components within the TME. In this review, the authors shed the light on the regulatory role of IL-10 in the TME of several malignant contexts. Moreover, detailed epigenomic and pharmacogenomic approaches for the regulation of IL-10 were presented and discussed.

Phytochemical-derived tumor-associated macrophage remodeling strategy using Phoenix dactylifera L. boosted photodynamic therapy in melanoma via H19/iNOS/PD-L1 axis

BACKGROUND

The tumor microenvironment (TME) represents a barrier to PDT efficacy among melanoma patients. The aim of this study is to employ a novel muti-tactic TME-remodeling strategy via repolarization of tumor-associated macrophages (TAMs), the main TME immune cells in melanoma, from the pro-tumor M2 into the antitumor M1 phenotype using Phoenix dactylifera L. (date palm) in combination with PDT.

METHODS

Screening of different date cultivars was employed to choose extracts of selective toxicity to melanoma and TAMs, not normal macrophages. Potential extracts were then fractionated and characterized by gas chromatography-mass spectrometry (GC-MS). Finally, the efficacy and the potential molecular mechanism of the co-treatment were portrayed via quantitative real-time polymerase chain reaction (qRT-PCR) analysis.

RESULTS

Initial screening resulted in the selection of the two Phoenix dactylifera L. cultivars Safawi and Sukkari methanolic extracts. Sukkari showed superior capacity to revert TAM phenotype into M1 as well as more prominent upregulation of M1 markers and repression of melanoma immunosuppressive markers relative to positive control (resiquimod). Molecularly, it was shown that PDT of melanoma cells in the presence of the secretome of repolarized TAMs surpassed the monotherapy via the modulation of the H19/iNOS/PD-L1immune-regulatory axis.

CONCLUSION

This study highlights the potential utilization of nutraceuticals in combination with PDT in the treatment of melanoma to provide a dual activity through alleviating the immune suppressive TME and potentiating the anti-tumor responses.

A Snapshot of Photoresponsive Liposomes in Cancer Chemotherapy and Immunotherapy: Opportunities and Challenges

To provide precise medical regimens, photonics technologies have been involved in the field of nanomedicine. Phototriggered liposomes have been cast as promising nanosystems that achieve controlled release of payloads in several pathological conditions such as cancer, autoimmune, and infectious diseases. In contrast to the conventional liposomes, this photoresponsive element greatly improves therapeutic efficacy and reduces the adverse effects of gene/drug therapy during treatment. Recently, cancer immunotherpay has been one of the hot topics in the field of oncology due to the great success and therapeutic benefits that were well-recognized by the patients. However, several side effects have been encountered due to the unmonitored augmentation of the immune system. This Review highlights the most recent advancements in the development of photoresponsive liposome nanosystems in the field of oncology, with a specific emphasis on challenges and opportunities in the field of cancer immunotherapy.

Dual targeting of H2S synthesizing enzymes; cystathionine β-synthase and cystathionine γ-lyase by miR-939-5p effectively curbs triple negative breast cancer

Introduction

Hydrogen sulfide (H2S) has been recently scrutinized for its critical role in aggravating breast cancer (BC) tumorigenicity. Several cancers aberrantly express H2S synthesizing enzymes; Cystathionine-β-synthase (CBS) and cystathionine-γ-lyase (CSE). However, their levels and interdependence in BC require further studies.

Objectives

Firstly, this study aimed to demonstrate a comparative expression profile of H2S synthesizing enzymes in BC vs normal tissue. Moreover, to investigate the reciprocal relationship between CBS and CSE and highlight the importance of dual targeting. Finally, to search for a valid dual repressor of the H2S synthesizing enzymes that could cease H2S production and reduce TNBC pathogenicity.

Methods

Pairwise analysis of tumor vs. normal tissues of 40 BC patients was carried out. The TNBC cell line MDA-MB-231 was transfected with oligonucleotides to study the H2S mediated molecular mechanisms. In silico screening was performed to identify dual regulator(s) for CBS and CSE. Gene expression analysis was performed using qRT-PCR and was confirmed on protein level using Western blot. TNBC hallmarks were evaluated using MTT, migration, and clonogenicity assays. H2S levels were detected using a AzMc fluorescent probe.

Results

BC tissues exhibited elevated levels of both CBS and CSE. Interestingly, upon CBS knockdown, CSE levels increased compensating for H2S production in TNBC cells, underlining the importance of dually targeting both enzymes in TNBC. In silico screening suggested miR-939-5p as a regulator of both CBS and CSE with high binding scores. Low expression levels of miR-939-5p were found in BC tissues, especially the aggressive subtypes. Ectopic expression of miR-939-5p significantly repressed CBS and CSE transcript and protein levels, diminished H2S production and attenuated TNBC hallmarks. Moreover, it improved the immune surveillance potency of TNBC cells through up regulating the NKG2D ligands, MICB and ULBP2 and reducing the immune suppressive cytokine IL-10.

Conclusion

This study sheds light on the reciprocal relationship between CBS and CSE and on the importance of their dual targeting, particularly in TNBC. It also postulates miR-939-5p as a potent dual repressor for CBS and CSE overcoming their redundancy in H2S production, a mechanism that can potentially attenuate TNBC oncogenicity and improves the immunogenic response.

Decoding hepatocarcinogenesis from a noncoding RNAs perspective

Being a leading lethal malignancy worldwide, the pathophysiology of hepatocellular carcinoma (HCC) has gained a lot of interest. Yet, underlying mechanistic basis of the liver tumorigenesis is poorly understood. The role of some coding genes and their respective translated proteins, then later on, some noncoding RNAs (ncRNAs) such as microRNAs have been extensively studied in context of HCC pathophysiology; however, the implication of long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) in HCC is indeed less investigated. As a subclass of the ncRNAs which has been elusive for long time ago, lncRNAs was found to be involved in plentiful cellular functions such as DNA, RNA, and proteins regulation. Hence, it is undisputed that lncRNAs dysregulation profoundly contributes to HCC via diverse etiologies. Accordingly, lncRNAs represent a hot research topic that requires prime focus in HCC. In this review, the authors discuss breakthrough discoveries involving lncRNAs and circRNAs dysregulation that have contributed to the contemporary concepts of HCC pathophysiology and how these concepts could be leveraged as potential novel diagnostic and prognostic HCC biomarkers. Further, this review article sheds light on future trends, thereby discussing the pathological roles of lncRNAs and circRNAs in HCC proliferation, migration, and epithelial-to-mesenchymal transition. Along this line of reasoning, future recommendations of how these targets could be exploited to achieve effective HCC-related drug development is highlighted.

Let-7a/cMyc/CCAT1/miR-17-5p Circuit Re-sensitizes Atezolizumab Resistance in Triple Negative Breast Cancer through Modulating PD-L1

BACKGROUND

Triple negative breast cancer (TNBC) is an immunogenically hot tumor. The immune checkpoint blockades (ICBs) have been recently emerged as promising therapeutic candidates for several malignancies including TNBC. Yet, the development of innate and/or adaptive resistance by TNBC patients towards ICBs such as programmed death-ligand 1 (PD-L1) inhibitors (e.g. Atezolizumab) shed the light on importance of identifying the underlying mechanisms regulating PD-L1 in TNBC. Recently, it was reported that non-coding RNAs (ncRNAs) perform a fundamental role in regulating PD-L1 expression in TNBC. Hence, this study aims to explore a novel ncRNA axis tuning PD-L1 in TNBC patients and investigate its possible involvement in fighting Atezolizumab resistance.

METHODS

In-silico screening was executed to identify ncRNAs that could potentially target PD-L1. Screening of PD-L1 and the nominated ncRNAs (miR-17-5p, let-7a and CCAT1 lncRNA) was performed in BC patients and cell lines. Ectopic expression and/or knockdown of respective ncRNAs were performed in MDA-MB-231. Cellular viability, migration and clonogenic capacities were evaluated using MTT, scratch assay and colony-forming assay, respectively.

RESULTS

PD-L1 was upregulated in BC patients, especially in TNBC patients. PD-L1 is positively associated with lymph node metastasis and high Ki-67 in recruited BC patients. Let-7a and miR-17-5p were nominated as potential regulators of PD-L1. Ectopic expression of let-7a and miR-17-5p caused a noticeable reduction in PD-L1 levels in TNBC cells. In order to investigate the whole ceRNA circuit regulating PD-L1 in TNBC, intensive bioinformatic studies were performed. The lncRNA, Colon Cancer-associated transcript 1 (CCAT1), was reported to target PD-L1 regulating miRNAs. Results showed that CCAT1 is an upregulated oncogenic lncRNA in TNBC patients and cell lines. CCAT1 siRNAs induced a noticeable reduction in PD-L1 levels and a marked increase in miR-17-5p level, building up a novel regulatory axis CCAT1/miR-17-5p/PD-L1 in TNBC cells that was tuned by the let-7a/c-Myc engine. On the functional level, co-treatment of CCAT-1 siRNAs and let-7a mimics efficiently relieved Atezolizumab resistance in MDA-MB-231 cells.

CONCLUSION

The present study revealed a novel PD-L1 regulatory axis via targeting let-7a/c-Myc/CCAT/miR-17-5p. Additionally, it sheds the light on the potential combinational role of CCAT-1 siRNAs and Let-7a mimics in relieving Atezolizumab resistance in TNBC patients.

The Role of Different Types of microRNA in the Pathogenesis of Breast and Prostate Cancer

Micro ribonucleic acids (microRNAs or miRNAs) form a distinct subtype of non-coding RNA and are widely recognized as one of the most significant gene expression regulators in mammalian cells. Mechanistically, the regulation occurs through microRNA binding with its response elements in the 3'-untranslated region of target messenger RNAs (mRNAs), resulting in the post-transcriptional silencing of genes, expressing target mRNAs. Compared to small interfering RNAs, microRNAs have more complex regulatory patterns, making them suitable for fine-tuning gene expressions in different tissues. Dysregulation of microRNAs is well known as one of the causative factors in malignant cell growth. Today, there are numerous data points regarding microRNAs in different cancer transcriptomes, the specificity of microRNA expression changes in various tissues, and the predictive value of specific microRNAs as cancer biomarkers. Breast cancer (BCa) is the most common cancer in women worldwide and seriously impairs patients' physical health. Its incidence has been predicted to rise further. Mounting evidence indicates that microRNAs play key roles in tumorigenesis and development. Prostate cancer (PCa) is one of the most commonly diagnosed cancers in men. Different microRNAs play an important role in PCa. Early diagnosis of BCa and PCa using microRNAs is very useful for improving individual outcomes in the framework of predictive, preventive, and personalized (3P) medicine, thereby reducing the economic burden. This article reviews the roles of different types of microRNA in BCa and PCa progression.

Noncoding RNA actions through IGFs and IGF binding proteins in cancer

The insulin-like growth factors (IGFs) and their regulatory proteins—IGF receptors and binding proteins—are strongly implicated in cancer progression and modulate cell survival and proliferation, migration, angiogenesis and metastasis. By regulating the bioavailability of the type-1 IGF receptor (IGF1R) ligands, IGF-1 and IGF-2, the IGF binding proteins (IGFBP-1 to -6) play essential roles in cancer progression. IGFBPs also influence cell communications through pathways that are independent of IGF1R activation. Noncoding RNAs (ncRNAs), which encompass a variety of RNA types including microRNAs (miRNAs) and long-noncoding RNAs (lncRNAs), have roles in multiple oncogenic pathways, but their many points of intersection with IGF axis functions remain to be fully explored. This review examines the functional interactions of miRNAs and lncRNAs with IGFs and their binding proteins in cancer, and reveals how the IGF axis may mediate ncRNA actions that promote or suppress cancer. A better understanding of the links between ncRNA and IGF pathways may suggest new avenues for prognosis and therapeutic intervention in cancer. Further, by exploring examples of intersecting ncRNA-IGF pathways in non-cancer conditions, it is proposed that new opportunities for future discovery in cancer control may be generated.