Insulin-like growth factor 2 receptor is a key immune-related gene that is correlated with a poor prognosis in patients with triple-negative breast cancer: A bioinformatics analysis

Potential therapeutic targets for colorectal cancer and its subsites: evidence from the proteome-wide Mendelian randomization analyses

Background

Colorectal cancer (CRC) is the most common malignant tumor of the digestive tract worldwide, however, the potential targets for CRC and its subsites (colon cancer & rectum cancer) are less known. The aim of this study is to explore potential therapeutic targets for CRC.

Methods

A proteome-wide genome-wide association studies (GWAS) in 35,559 Icelanders with 4,907 plasma proteins was used as instrumental variables (P value <5×10-8). The discovery stage consisted of the CRC GWAS with the largest sample size (CRC: 14,886 cases; colon: 3,793 cases; rectum: 2,091 cases). The significant proteins were further validated in the FinnGen study with 5,458 CRC cases (3,292 colon + 2,017 rectum). We identified relevant protein loci in CRC by two sample Mendelian randomization (MR) [false discovery rate (FDR) <0.05], colocalization analysis was used to further determine the relevance between CRC and plasma proteins, enrichment analysis and drug prediction were used to predict protein function.

Results

A total of 31 proteins were found to be in robust causal associations with CRC and the proteins' effects displayed anatomic site-specificity in MR analysis. The subsequent colocalization analysis pinpointed that CHDRL2 had a shared region with CRC and its two subsites, suggesting the importance of targeting it. Besides, IGF2R and ENPEP displayed anatomic site-specificity to colon cancer while ASRGL1 was strongly correlated only with the risk of rectal cancer. Enrichment analysis revealed functions of these proteins in CRC, and DrugBank showed their target drug.

Conclusions

In summary, our study has identified a common protein, CHDRL2, as the drug targets for CRC and its subsites. Besides, IGF2R and ENPEP displayed anatomic site-specificity to colon cancer while ASRGL1 was strongly correlated only with the risk of rectal cancer.

Structure, unique biological properties, and mechanisms of action of transforming growth factor β

Transforming growth factor β (TGF-β) is a ubiquitous molecule that is extremely conserved structurally and plays a systemic role in human organism. TGF-β is a homodimeric molecule consisting of two subunits joined through a disulphide bond. In mammals, three genes code for TGF-β1, TGF-β2, and TGF-β3 isoforms of this cytokine with a dominating expression of TGF-β1. Virtually, all normal cells contain TGF-β and its specific receptors. Considering the exceptional role of fine balance played by the TGF-β in anumber of physiological and pathological processes in human body, this cytokine may be proposed for use in medicine as an immunosuppressant in transplantology, wound healing and bone repair. TGFb itself is an important target in oncology. Strategies for blocking members of TGF-β signaling pathway as therapeutic targets have been considered. In this review, signalling mechanisms of TGF-β1 action are addressed, and their role in physiology and pathology with main focus on carcinogenesis are described.

RNA-Independent Regulatory Functions of lncRNA in Complex Disease

During the metagenomics era, high-throughput sequencing efforts both in mice and humans indicate that non-coding RNAs (ncRNAs) constitute a significant fraction of the transcribed genome. During the past decades, the regulatory role of these non-coding transcripts along with their interactions with other molecules have been extensively characterized. However, the study of long non-coding RNAs (lncRNAs), an ncRNA regulatory class with transcript lengths that exceed 200 nucleotides, revealed that certain non-coding transcripts are transcriptional "by-products", while their loci exert their downstream regulatory functions through RNA-independent mechanisms. Such mechanisms include, but are not limited to, chromatin interactions and complex promoter-enhancer competition schemes that involve the underlying ncRNA locus with or without its nascent transcription, mediating significant or even exclusive roles in the regulation of downstream target genes in mammals. Interestingly, such RNA-independent mechanisms often drive pathological manifestations, including oncogenesis. In this review, we summarize selective examples of lncRNAs that regulate target genes independently of their produced transcripts.

Insulin Receptor Isoforms and Insulin Growth Factor-like Receptors: Implications in Cell Signaling, Carcinogenesis, and Chemoresistance

This comprehensive review thoroughly explores the intricate involvement of insulin receptor (IR) isoforms and insulin-like growth factor receptors (IGFRs) in the context of the insulin and insulin-like growth factor (IGF) signaling (IIS) pathway. This elaborate system encompasses ligands, receptors, and binding proteins, giving rise to a wide array of functions, including aspects such as carcinogenesis and chemoresistance. Detailed genetic analysis of IR and IGFR structures highlights their distinct isoforms, which arise from alternative splicing and exhibit diverse affinities for ligands. Notably, the overexpression of the IR-A isoform is linked to cancer stemness, tumor development, and resistance to targeted therapies. Similarly, elevated IGFR expression accelerates tumor progression and fosters chemoresistance. The review underscores the intricate interplay between IRs and IGFRs, contributing to resistance against anti-IGFR drugs. Consequently, the dual targeting of both receptors could present a more effective strategy for surmounting chemoresistance. To conclude, this review brings to light the pivotal roles played by IRs and IGFRs in cellular signaling, carcinogenesis, and therapy resistance. By precisely modulating these receptors and their complex signaling pathways, the potential emerges for developing enhanced anti-cancer interventions, ultimately leading to improved patient outcomes.

A proteomic signature and potential pharmacological opportunities in the adaptive resistance to MEK and PI3K kinase inhibition in pancreatic cancer cells

Pancreatic cancer is one of the most lethal cancer types and is becoming a leading cause of cancer-related deaths. The limited benefit offered by chemotherapy agents has propelled the search for alternative approaches that target specific molecular drivers of cancer growth and progression. Mutant KRas and effector pathways Raf/MEK/ERK and PI3K/Akt are key players in pancreatic cancer; however, preclinical studies have shown adaptive tumour response to combined MEK and PI3K kinase inhibition leading to treatment resistance. There is a critical unmet need to decipher the molecular basis underlying adaptation to this targeted approach. Here, we aimed to identify common protein expression alterations associated with adaptive resistance in KRas-mutant pancreatic cancer cells, and test if it can be overcome by selected already available small molecule drugs. We found a group of 14 proteins with common expression change in resistant cells, including KRas, caveolin-1, filamin-a, eplin, IGF2R and cytokeratins CK-8, -18 and -19. Notably, several proteins have previously been observed in pancreatic cancer cells with intrinsic resistance to the combined kinase inhibition treatment, suggesting a proteomic signature. We also found that resistant cells are sensitive to small molecule drugs ERK inhibitor GDC-0994, S6K1 inhibitor DG2 and statins.