The autocrine loop of ALK receptor and ALKAL2 ligand is an actionable target in consensus molecular subtype 1 colon cancer

Large-scale analysis of cell-cell communication reveals angiogenin-dependent tumor progression in clear cell renal cell carcinoma

Cellular crosstalk in the tumor microenvironment (TME) is still largely uncharacterized, while it plays an essential role in shaping immunosuppression or anti-tumor response. Large-scale analyses are needed to better decipher cell-cell communication in cancer. In this work, we used original and publicly available single-cell RNA sequencing (scRNAseq) data to characterize in-depth the communication networks in human clear cell renal cell carcinoma (ccRCC). We identified 50 putative communication channels specifically used by cancer cells to interact with other cells, including two novel angiogenin-mediated interactions. Expression of angiogenin and its receptors was validated at the protein level in primary ccRCC. Mechanistically, angiogenin enhanced ccRCC cell line proliferation and down-regulated secretion of IL-6, IL-8, and MCP-1 proinflammatory molecules. This study provides novel biological insights into molecular mechanisms of ccRCC, and suggests angiogenin and its receptors as potential therapeutic targets in clear cell renal cancer.

Autocrine regulation of tumor cell repopulation by Hsp70-HMGB1 alarmin complex

BACKGROUND

Cancer recurrence is regulated by a variety of factors, among which is the material of dying tumor cells; it is suggested that remaining after anti-cancer therapy tumor cells receive a signal from proteins called damage-associated molecular patterns (DAMPs), one of which is heat shock protein 70 (Hsp70).

METHODS

Two models of tumor repopulation were employed, based on minimal population of cancer cells and application of conditioned medium (CM). To deplete the CMs of Hsp70 affinity chromatography on ATP-agarose and immunoprecipitation were used. Cell proliferation and the dynamics of cell growth were measured using MTT assay and xCELLigence technology; cell growth markers were estimated using qPCR and with the aid of ELISA for prostaglandin E detection. Immunoprecipitation followed by mass-spectrometry was employed to identify Hsp70-binding proteins and protein-protein interaction assays were developed to reveal the above protein complexes.

RESULTS

It was found that CM of dying tumor cells contains tumor regrowth-initiating factors and the removal of one of them, Hsp70, caused a reduction in the relapse-activating capacity. The pull out of Hsp70 alone using ATP-agarose had no effect on repopulation, while the immunodepletion of Hsp70 dramatically reduced its repopulation activity. Using proteomic and immunochemical approaches, we showed that Hsp70 in conditioned medium binds and binds another abundant alarmin, the High Mobility Group B1 (HMGB1) protein; the complex is formed in tumor cells treated with anti-cancer drugs, persists in the cytosol and is further released from dying tumor cells. Recurrence-activating power of Hsp70-HMGB1 complex was proved by the enhanced expression of proliferation markers, Ki67, Aurka and MCM-10 as well as by increase of prostaglandin E production and autophagy activation. Accordingly, dissociating the complex with Hsp70 chaperone inhibitors significantly inhibited the pro-growth effects of the above complex, in both in vitro and in vivo tumor relapse models.

CONCLUSIONS

These data led us to suggest that the abundance of the Hsp70-HMGB1 complex in the extracellular matrix may serve as a novel marker of relapse state in cancer patients, while specific targeting of the complex may be promising in the treatment of cancers with a high risk of recurrence.

Multifaceted Roles of ALK Family Receptors and Augmentor Ligands in Health and Disease: A Comprehensive Review

This review commemorates the 10-year anniversary of the discovery of physiological ligands Augα (Augmentor α; ALKAL2; Fam150b) and Augβ (Augmentor β; ALKAL1; Fam150a) for anaplastic lymphoma kinase (ALK) and leukocyte tyrosine kinase (LTK), previously considered orphan receptors. This manuscript provides an in-depth review of the biophysical and cellular properties of ALK family receptors and their roles in cancer, metabolism, pain, ophthalmology, pigmentation, central nervous system (CNS) function, and reproduction. ALK and LTK receptors are implicated in the development of numerous cancers, and targeted inhibition of their signaling pathways can offer therapeutic benefits. Additionally, ALK family receptors are involved in regulating body weight and metabolism, modulating pain signaling, and contributing to eye development and pigmentation. In the CNS, these receptors play a role in synapse modulation, neurogenesis, and various psychiatric pathologies. Lastly, ALK expression is linked to reproductive functions, with potential implications for patients undergoing ALK inhibitor therapy. Further research is needed to better understand the complex interactions of ALK family receptors and Aug ligands and to repurpose targeted therapy for a wide range of human diseases.

Principles of Molecular Utility for CMS Classification in Colorectal Cancer Management

Colorectal cancer (CRC) is the second cause of cancer-related deaths in both sexes globally and presents different clinical outcomes that are described by a range of genomic and epigenomic alterations. Despite the advancements in CRC screening plans and treatment strategies, the prognosis of CRC is dismal. In the last two decades, molecular biomarkers predictive of prognosis have been identified in CRC, although biomarkers predictive of treatment response are only available for specific biological drugs used in stage IV CRC. Translational clinical trials mainly based on "omic" strategies allowed a better understanding of the biological heterogeneity of CRCs. These studies were able to classify CRCs into subtypes mainly related to prognosis, recurrence risk, and, to some extent, also to treatment response. Accordingly, the comprehensive molecular characterizations of CRCs, including The Cancer Genome Atlas (TCGA) and consensus molecular subtype (CMS) classifications, were presented to improve the comprehension of the genomic and epigenomic landscapes of CRCs for a better patient management. The CMS classification obtained by the CRC subtyping consortium categorizes CRC into four consensus molecular subtypes (CMS1-4) characterized by different prognoses. In this review, we discussed the CMS classification in different settings with a focus on its relationships with precursor lesions, tumor immunophenotype, and gut microbiota, as well as on its role in predicting prognosis and/or response to pharmacological treatments, as a crucial step towards precision medicine.

Pharmacological targeting of the receptor ALK inhibits tumorigenicity and overcomes chemoresistance in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive disease characterized by its metastatic potential and chemoresistance. These traits are partially attributable to the highly tumorigenic pancreatic cancer stem cells (PaCSCs). Interestingly, these cells show unique features in order to sustain their identity and functionality, some of them amenable for therapeutic intervention. Screening of phospho-receptor tyrosine kinases revealed that PaCSCs harbored increased activation of anaplastic lymphoma kinase (ALK). We subsequently demonstrated that oncogenic ALK signaling contributes to tumorigenicity in PDAC patient-derived xenografts (PDXs) by promoting stemness through ligand-dependent activation. Indeed, the ALK ligands midkine (MDK) or pleiotrophin (PTN) increased self-renewal, clonogenicity and CSC frequency in several in vitro local and metastatic PDX models. Conversely, treatment with the clinically-approved ALK inhibitors Crizotinib and Ensartinib decreased PaCSC content and functionality in vitro and in vivo, by inducing cell death. Strikingly, ALK inhibitors sensitized chemoresistant PaCSCs to Gemcitabine, as the most used chemotherapeutic agent for PDAC treatment. Consequently, ALK inhibition delayed tumor relapse after chemotherapy in vivo by effectively decreasing the content of PaCSCs. In summary, our results demonstrate that targeting the MDK/PTN-ALK axis with clinically-approved inhibitors impairs in vivo tumorigenicity and chemoresistance in PDAC suggesting a new treatment approach to improve the long-term survival of PDAC patients.

Genome-wide screening for differentially methylated long noncoding RNAs identifies LIFR-AS1 as an epigenetically regulated lncRNA that inhibits the progression of colorectal cancer

Background

Aberrant DNA methylation is an epigenetic marker that has been linked to the pathogenesis of colorectal cancer (CRC). Long noncoding RNAs (lncRNAs) have been increasingly identified to be associated with tumorigenic processes of CRC. Identifying epigenetically dysregulated lncRNAs and characterizing their effects during carcinogenesis are focuses of cancer research.

Methods

Differentially methylated loci and expressed lncRNAs were identified by integrating DNA methylome and transcriptome analyses using The Cancer Genome Atlas database. Bisulfite sequencing PCR (BSP) was performed to analyze LIFR-AS1 promoter methylation status. The functional roles of LIFR-AS1 in CRC were determined by in vitro and in vivo experiments.

Results

We identified a novel hypermethylated lncRNA, LIFR-AS1, that was downregulated and associated with tumorigenesis, metastasis, and poor prognosis in CRC. High methylation burden of LIFR-AS1 indicated a poor survival of CRC patients. Promoter hypermethylation of LIFR-AS1 in tumor tissues was confirmed by BSP. Functional assays revealed that LIFR-AS1 could competitively bind to hsa-miR-29b-3p, and repressed colon cancer cell proliferation, colony formation and invasion. LIFR-AS1 also inhibited tumor growth in a mouse xenograft model of CRC.

Conclusions

Our results showed that the identified DNA methylation-dysregulated lncRNAs may be potential biomarkers and highlighted a role for LIFR-AS1 as a tumor suppressor in CRC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-022-01361-0.