DNA repair in cancer initiation, progression, and therapy-a double-edged sword

Increasing DNA damage sensitivity through corylin-mediated inhibition of homologous recombination

BACKGROUND

DNA repair allows the survival of cancer cells. Therefore, the development of DNA repair inhibitors is a critical need for sensitizing cancers to chemoradiation. Sae2CtIP has specific functions in initiating DNA end resection, as well as coordinating cell cycle checkpoints, and it also greatly interacts with the DDR at different levels.

RESULTS

In this study, we demonstrated that corylin, a potential sensitizer, causes deficiencies in DNA repair and DNA damage checkpoints in yeast cells. More specifically, corylin increases DNA damage sensitivity through the Sae2-dependent pathway and impairs the activation of Mec1-Ddc2, Rad53-p and γ-H2A. In breast cancer cells, corylin increases apoptosis and reduces proliferation following Dox treatment by inhibiting CtIP. Xenograft assays showed that treatment with corylin combined with Dox significantly reduced tumor growth in vivo.

CONCLUSIONS

Our findings herein delineate the mechanisms of action of corylin in regulating DNA repair and indicate that corylin has potential long-term clinical utility as a DDR inhibitor.

NRDE2 deficiency impairs homologous recombination repair and sensitizes hepatocellular carcinoma to PARP inhibitors

To identify novel susceptibility genes for hepatocellular carcinoma (HCC), we performed a rare-variant association study in Chinese populations consisting of 2,750 cases and 4,153 controls. We identified four HCC-associated genes, including NRDE2, RANBP17, RTEL1, and STEAP3. Using NRDE2 (index rs199890497 [p.N377I], p = 1.19 × 10-9) as an exemplary candidate, we demonstrated that it promotes homologous recombination (HR) repair and suppresses HCC. Mechanistically, NRDE2 binds to the subunits of casein kinase 2 (CK2) and facilitates the assembly and activity of the CK2 holoenzyme. This NRDE2-mediated enhancement of CK2 activity increases the phosphorylation of MDC1 and then facilitates the HR repair. These functions are eliminated almost completely by the NRDE2-p.N377I variant, which sensitizes the HCC cells to poly(ADP-ribose) polymerase (PARP) inhibitors, especially when combined with chemotherapy. Collectively, our findings highlight the relevance of the rare variants to genetic susceptibility to HCC, which would be helpful for the precise treatment of this malignancy.

Functional roles and cancer variants of the bifunctional glycosylase NEIL2

Over 70,000 DNA lesions occur in the cell every day, and the inability to properly repair them can lead to mutations and destabilize the genome, resulting in carcinogenesis. The base excision repair (BER) pathway is critical for maintaining genomic integrity by repairing small base lesions, abasic sites and single-stranded breaks. Monofunctional and bifunctional glycosylases initiate the first step of BER by recognizing and excising specific base lesions, followed by DNA end processing, gap filling, and finally nick sealing. The Nei-like 2 (NEIL2) enzyme is a critical bifunctional DNA glycosylase in BER that preferentially excises cytosine oxidation products and abasic sites from single-stranded, double-stranded, and bubble-structured DNA. NEIL2 has been implicated to have important roles in several cellular functions, including genome maintenance, participation in active demethylation, and modulation of the immune response. Several germline and somatic variants of NEIL2 with altered expression and enzymatic activity have been reported in the literature linking them to cancers. In this review, we provide an overview of NEIL2 cellular functions and summarize current findings on NEIL2 variants and their relationship to cancer.

Integration of scRNA and bulk RNA-sequence to construct the 5-gene molecular prognostic model based on the heterogeneity of thyroid carcinoma endothelial cell

Thyroid cancer (TC) is a kind of cancer with high heterogeneity, which leads to significant difference in prognosis. The prognostic molecular processes are not well understood. Cancer cells and tumor microenvironment (TME) cells jointly determine the heterogeneity. However, quite a little attention was paid to cells in the TME in the past years. In this study, we not only reveal that endothelial cells (ECs) are strongly associated with the progress of papillary thyroid cancer (PTC) using single-cell RNA-seq (scRNA-seq) data downloaded from Gene Expression Omnibus (GEO) and WGCNA, but also screen 5 crucial genes of ECs: CLDN5, ABCG2, NOTCH4, PLAT, and TMEM47. Furthermore, the 5-gene molecular prognostic model is constructed, which can predict how well a patient will do on PD-L1 blockade immunotherapy for TC and evaluate prognosis. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis demonstrates that PLAT is decreased in TC and the increase of PLAT can restrain the migratory capacity of TC cells. Meanwhile, in TC cells, PLAT suppresses VEGFa/VEGFR2-mediated human umbilical vascular endothelial cell (HUVEC) proliferation and tube formation. Totally, we construct the 5-gene molecular prognostic model from the perspective of EC and provide a new idea for immunotherapy of TC.

Rationally Designed DNA-Based Scaffolds and Switching Probes for Protein Sensing

The detection of a protein analyte and use of this type of information for disease diagnosis and physiological monitoring requires methods with high sensitivity and specificity that have to be also easy to use, rapid and, ideally, single step. In the last 10 years, a number of DNA-based sensing methods and sensors have been developed in order to achieve quantitative readout of protein biomarkers. Inspired by the speed, specificity, and versatility of naturally occurring chemosensors based on structure-switching biomolecules, significant efforts have been done to reproduce these mechanisms into the fabrication of artificial biosensors for protein detection. As an alternative, in scaffold DNA biosensors, different recognition elements (e.g., peptides, proteins, small molecules, and antibodies) can be conjugated to the DNA scaffold with high accuracy and precision in order to specifically interact with the target protein with high affinity and specificity. They have several advantages and potential, especially because the transduction signal can be drastically enhanced. Our aim here is to provide an overview of the best examples of structure switching-based and scaffold DNA sensors, as well as to introduce the reader to the rational design of innovative sensing mechanisms and strategies based on programmable functional DNA systems for protein detection.

Nanovaccines: An effective therapeutic approach for cancer therapy

Cancer vaccines hold considerable promise for the immunotherapy of solid tumors. Nanomedicine offers several strategies for enhancing vaccine effectiveness. In particular, molecular or (sub) cellular vaccines can be delivered to the target lymphoid tissues and cells by nanocarriers and nanoplatforms to increase the potency and durability of antitumor immunity and minimize negative side effects. Nanovaccines use nanoparticles (NPs) as carriers and/or adjuvants, offering the advantages of optimal nanoscale size, high stability, ample antigen loading, high immunogenicity, tunable antigen presentation, increased retention in lymph nodes, and immunity promotion. To induce antitumor immunity, cancer vaccines rely on tumor antigens, which are administered in the form of entire cells, peptides, nucleic acids, extracellular vesicles (EVs), or cell membrane-encapsulated NPs. Ideal cancer vaccines stimulate both humoral and cellular immunity while overcoming tumor-induced immune suppression. Herein, we review the key properties of nanovaccines for cancer immunotherapy and highlight the recent advances in their development based on the structure and composition of various (including synthetic and semi (biogenic) nanocarriers. Moreover, we discuss tumor cell-derived vaccines (including those based on whole-tumor-cell components, EVs, cell membrane-encapsulated NPs, and hybrid membrane-coated NPs), nanovaccine action mechanisms, and the challenges of immunocancer therapy and their translation to clinical applications.

Improving targeted small molecule drugs to overcome chemotherapy resistance

BACKGROUND

Conventional cancer treatments face the challenge of therapeutic resistance, which causes poor treatment outcomes. The use of combination therapies can improve treatment results in patients and is one of the solutions to overcome this challenge. Chemotherapy is one of the conventional treatments that, due to the non-targeted and lack of specificity in targeting cancer cells, can cause serious complications in the short and long-term for patients by damaging healthy cells. Also, the employment of a wide range of strategies for chemotherapy resistance by cancer cells, metastasis, and cancer recurrence create serious problems to achieve the desired results of chemotherapy. Accordingly, targeted therapies can be used as a combination treatment with chemotherapy to both cause less damage to healthy cells, which as a result, they reduce the side effects of chemotherapy, and by targeting the factors that cause therapeutic challenges, can improve the results of chemotherapy in patients.

RECENT FINDINGS

Small molecules are one of the main targeted therapies that can be used for diverse targets in cancer treatment due to their penetration ability and characteristics. However, small molecules in cancer treatment are facing obstacles that a better understanding of cancer biology, as well as the mechanisms and factors involved in chemotherapy resistance, can lead to the improvement of this type of major targeted therapy.

CONCLUSION

In this review article, at first, the challenges that lead to not achieving the desired results in chemotherapy and how cancer cells can be resistant to chemotherapy are examined, and at the end, research areas are suggested that more focusing on them, can lead to the improvement of the results of using targeted small molecules as an adjunctive treatment for chemotherapy in the conditions of chemotherapy resistance and metastasis of cancer cells.

Identifying diseases associated with Post-COVID syndrome through an integrated network biology approach

A growing body of research shows that COVID-19 is now recognized as a multi-organ disease with a wide range of manifestations that can have long-lasting repercussions, referred to as post-COVID-19 syndrome. It is unknown why the vast majority of COVID-19 patients develop post-COVID-19 syndrome, or why patients with pre-existing disorders are more likely to experience severe COVID-19. This study used an integrated network biology approach to obtain a comprehensive understanding of the relationship between COVID-19 and other disorders. The approach involved building a PPI network with COVID-19 genes and identifying highly interconnected regions. The molecular information contained within these subnetworks, as well as the pathway annotations, were used to reveal the link between COVID-19 and other disorders. Using Fisher's exact test and disease-specific gene information, significant COVID-19-disease associations were discovered. The study discovered diseases that affect multiple organs and organ systems, thus proving the theory of multiple organ damage caused by COVID-19. Cancers, neurological disorders, hepatic diseases, cardiac disorders, pulmonary diseases, and hypertensive diseases are just a few of the conditions linked to COVID-19. Pathway enrichment analysis of shared proteins revealed the shared molecular mechanism of COVID-19 and these diseases. The findings of the study shed new light on the major COVID-19-associated disease conditions and how their molecular mechanisms interact with COVID-19. The novelty of studying disease associations in the context of COVID-19 provides new insights into the management of rapidly evolving long-COVID and post-COVID syndromes, which have significant global implications.Communicated by Ramaswamy H. Sarma.

Germ line variant GFI1-36N affects DNA repair and sensitizes AML cells to DNA damage and repair therapy

ABSTRACT

Growth factor independence 1 (GFI1) is a DNA-binding transcription factor and a key regulator of hematopoiesis. GFI1-36N is a germ line variant, causing a change of serine (S) to asparagine (N) at position 36. We previously reported that the GFI1-36N allele has a prevalence of 10% to 15% among patients with acute myeloid leukemia (AML) and 5% to 7% among healthy Caucasians and promotes the development of this disease. Using a multiomics approach, we show here that GFI1-36N expression is associated with increased frequencies of chromosomal aberrations, mutational burden, and mutational signatures in both murine and human AML and impedes homologous recombination (HR)-directed DNA repair in leukemic cells. GFI1-36N exhibits impaired binding to N-Myc downstream-regulated gene 1 (Ndrg1) regulatory elements, causing decreased NDRG1 levels, which leads to a reduction of O6-methylguanine-DNA-methyltransferase (MGMT) expression levels, as illustrated by both transcriptome and proteome analyses. Targeting MGMT via temozolomide, a DNA alkylating drug, and HR via olaparib, a poly-ADP ribose polymerase 1 inhibitor, caused synthetic lethality in human and murine AML samples expressing GFI1-36N, whereas the effects were insignificant in nonmalignant GFI1-36S or GFI1-36N cells. In addition, mice that received transplantation with GFI1-36N leukemic cells treated with a combination of temozolomide and olaparib had significantly longer AML-free survival than mice that received transplantation with GFI1-36S leukemic cells. This suggests that reduced MGMT expression leaves GFI1-36N leukemic cells particularly vulnerable to DNA damage initiating chemotherapeutics. Our data provide critical insights into novel options to treat patients with AML carrying the GFI1-36N variant.

Inhibition of p300 increases cytotoxicity of cisplatin in pancreatic cancer cells

Pancreatic cancer is a notoriously deadly disease with a five-year survival rate around 10 percent. Since early detection of these tumors is difficult, pancreatic cancers are often diagnosed at advanced stages. At this point, genotoxic chemotherapeutics can be used to manage tumor growth. However, side effects of these drugs are severe, limiting the amount of treatment that can be given and resulting in sub-optimal dosing. Thus, there is an urgent need to identify chemo-sensitizing agents that can lower the effective dose of genotoxic agents and as a result reduce the side effects. Here, we use transformed and non-transformed pancreatic cell lines to evaluate DNA repair inhibitors as chemo-sensitizing agents. We used a novel next generation sequencing approach to demonstrate that pancreatic cancer cells have a reduced ability to faithfully repair DNA damage. We then determine the extent that two DNA repair inhibitors (CCS1477, a small molecule inhibitor of p300, and ART558, a small molecule inhibitor of polymerase theta) can exploit this repair deficiency to make pancreatic cancer cells more sensitive to cisplatin, a commonly used genotoxic chemotherapeutic. Immunofluorescence microscopy and cell viability assays show that CCS1477 delayed repair and significantly sensitized pancreatic cancer cells to cisplatin. The increased toxicity was not seen in a non-transformed pancreatic cell line. We also found that while ART558 sensitizes pancreatic cancer cells to cisplatin, it also sensitized non-transformed pancreatic cancer cells.

Advances in the structure, mechanism and targeting of chemoresistance-linked ABC transporters

Cancer cells frequently display intrinsic or acquired resistance to chemically diverse anticancer drugs, limiting therapeutic success. Among the main mechanisms of this multidrug resistance is the overexpression of ATP-binding cassette (ABC) transporters that mediate drug efflux, and, specifically, ABCB1, ABCG2 and ABCC1 are known to cause cancer chemoresistance. High-resolution structures, biophysical and in silico studies have led to tremendous progress in understanding the mechanism of drug transport by these ABC transporters, and several promising therapies, including irradiation-based immune and thermal therapies, and nanomedicine have been used to overcome ABC transporter-mediated cancer chemoresistance. In this Review, we highlight the progress achieved in the past 5 years on the three transporters, ABCB1, ABCG2 and ABCC1, that are known to be of clinical importance. We address the molecular basis of their broad substrate specificity gleaned from structural information and discuss novel approaches to block the function of ABC transporters. Furthermore, genetic modification of ABC transporters by CRISPR-Cas9 and approaches to re-engineer amino acid sequences to change the direction of transport from efflux to import are briefly discussed. We suggest that current information regarding the structure, mechanism and regulation of ABC transporters should be used in clinical trials to improve the efficiency of chemotherapeutics for patients with cancer.

High Risk of Heart Tumors after COVID-19

An emergence of evidence suggests that severe COVID-19 is associated with an increased risk of developing breast and gastrointestinal cancers. The aim of this research was to assess the risk of heart tumors development in patients who have had COVID-19.

METHODS

A comparative analysis of 173 heart tumors was conducted between 2016 and 2023. Immunohistochemical examination with antibodies against spike SARS-CoV-2 was performed on 21 heart tumors: 10 myxomas operated before 2020 (the control group), four cardiac myxomas, one proliferating myxoma, three papillary fibroelastomas, two myxofibrosarcomas, one chondrosarcoma resected in 2022-2023. Immunohistochemical analysis with antibodies against CD34 and CD68 was also conducted on the same 11 Post-COVID period heart tumors. Immunofluorescent examination with a cocktail of antibodies against spike SARS-CoV-2/CD34 and spike SARS-CoV-2/CD68 was performed in 2 cases out of 11 (proliferating myxoma and classic myxoma).

RESULTS

A 1.5-fold increase in the number of heart tumors by 2023 was observed, with a statistically significant increase in the number of myxomas. There was no correlation with vaccination, and no significant differences were found between patients from 2016-2019 and 2021-2023 in terms of gender, age, and cardiac rhythm dis-orders. Morphological examination revealed the expression of spike SARS-CoV-2 in tumor cells, endothelial cells, and macrophages in 10 out of 11 heart tumors.

CONCLUSION

The detection of SARS-CoV-2 persistence in endothelium and macrophages as well as in tumor cells of benign and malignant cardiac neoplasms, the increase in the number of these tumors, especially cardiac myxomas, after the pandemic by 2023 may indicate a trend toward an increased risk of cardiac neoplasms in COVID-19 patients, which re-quires further research on this issue and a search for new evidence.

Expression Profile, Molecular Association, and Clinical Significance of POLD4 in Glioblastoma

The POLD4 gene encodes a subunit (δ4) of DNA polymerase delta, which is a key enzyme involved in DNA replication and repair. Recent studies have suggested that POLD4 plays a crucial role in developing certain cancers. However, there is a lack of knowledge regarding the role of POLD4 in the context of glioblastoma (GBM). Therefore, in this study we have used various cancer bioinformatics tools to explore the role of POLD4 in glioblastoma. Data from various sources were accessed to analyze POLD4 gene expression and estimate tumor-infiltrating immune cells in glioblastoma. Methylation data were retrieved using the MEXPRESS web browser and analyzed. UALCAN webserver was used to analyze the protein expression of POLD4. Gene correlation and pathway enrichment analysis were performed using cBioPortal and GSEA software, respectively. Afterward, survival analysis was performed. POLD4 was significantly upregulated in glioblastoma at both gene and protein levels in GBM, and ROC curve analysis revealed it as a potential biomarker in glioblastoma. GSEA analysis of TCGA-GBM pan-cancer study exhibited that POLD4 expression was associated with critical pathways, such as interferon-gamma response, G2M checkpoint, inflammatory response, E2F targets, EMT transition, and KRAS signaling pathways. Furthermore, POLD4 expression was positively correlated with DNA methylation at 3 CpG sites, including Cg16509978, with a Pearson correlation coefficient value of 0.398 (p-value ≤ 0.01), while the promoter region had a positive correlation but was not significant. In addition, POLD4 is significantly linked with poor OS, PFS, and DFS. We also found association of POLD4 expression with altered immune cell infiltration. In conclusion, POLD4 is significantly upregulated in glioblastoma and may be used as a potential diagnostic or prognostic biomarker for GBM patients. However, to establish the same a large cohort study is needed. Using TCGA data and various cancer bioinformatics tools mentioned above we observed very high level of gene and protein expression of POLD4 in glioblastoma patients. The expression of POLD4 was significantly correlated with inflammatory and oncogenic pathways and it also has a significant correlation with adverse outcome in patients with glioblastoma.

Possible Genetic Risks from Heat-Damaged DNA in Food

The consumption of foods prepared at high temperatures has been associated with numerous health risks. To date, the chief identified source of risk has been small molecules produced in trace levels by cooking and reacting with healthy DNA upon consumption. Here, we considered whether the DNA in food itself also presents a hazard. We hypothesize that high-temperature cooking may cause significant damage to the DNA in food, and this damage might find its way into cellular DNA by metabolic salvage. We tested cooked and raw foods and found high levels of hydrolytic and oxidative damage to all four DNA bases upon cooking. Exposing cultured cells to damaged 2'-deoxynucleosides (particularly pyrimidines) resulted in elevated DNA damage and repair responses in the cells. Feeding a deaminated 2'-deoxynucleoside (2'-deoxyuridine), and DNA containing it, to mice resulted in substantial uptake into intestinal genomic DNA and promoted double-strand chromosomal breaks there. The results suggest the possibility of a previously unrecognized pathway whereby high-temperature cooking may contribute to genetic risks.

The role of the genomic mutation signature and tumor mutation burden on relapse risk prediction in head and neck squamous cell carcinoma after concurrent chemoradiotherapy

Personalized genetic profiling has focused on improving treatment efficacy and predicting risk stratification by identifying mutated genes and selecting targeted agents according to genetic testing. Therefore, we evaluated the role of genetic profiling and tumor mutation burden (TMB) using next-generation sequencing in patients with head and neck squamous cell carcinoma (HNSC). The relapse mutation signature (RMS) and chromatin remodeling mutation signature (CRMS) were explored to predict the risk of relapse in patients with HNSC treated with concurrent chemoradiotherapy (CCRT) with platinum-based chemotherapy. Patients in the high RMS and CRMS groups showed significantly shorter relapse-free survival than those in the low RMS and CRMS groups, respectively (p < 0.001 and p = 0.006). Multivariate Cox regression analysis showed that extranodal extension, CCRT response, and three somatic mutation profiles (TMB, RMS, and CRMS) were independent risk predictors for HNSC relapse. The predictive nomogram showed satisfactory performance in predicting relapse-free survival in patients with HNSC treated with CCRT.

Spontaneous cancer remission after COVID-19: insights from the pandemic and their relevance for cancer treatment

Early in the COVID-19 pandemic, it emerged that the risk of severe outcomes was greater in patients with co-morbidities, including cancer. The huge effort undertaken to fight the pandemic, affects the management of cancer care, influencing their outcome. Despite the high fatality rate of COVID-19 disease in cancer patients, rare cases of temporary or prolonged clinical remission from cancers after SARS-CoV-2 infection have been reported. We have reviewed sixteen case reports of COVID-19 disease with spontaneous cancer reduction of progression. Fourteen cases of remission following viral infections and two after anti-SARS-CoV-2 vaccination. The immune response to COVID-19, may be implicated in both tumor regression, and progression. Specifically, we discuss potential mechanisms which include oncolytic and priming hypotheses, that may have contributed to the cancer regression in these cases and could be useful for future options in cancer treatment.

Transcriptomic Analysis of CRISPR/Cas9-Mediated PARP1-Knockout Cells under the Influence of Topotecan and TDP1 Inhibitor

Topoisomerase 1 (TOP1) is an enzyme that regulates DNA topology and is essential for replication, recombination, and other processes. The normal TOP1 catalytic cycle involves the formation of a short-lived covalent complex with the 3' end of DNA (TOP1 cleavage complex, TOP1cc), which can be stabilized, resulting in cell death. This fact substantiates the effectiveness of anticancer drugs-TOP1 poisons, such as topotecan, that block the relegation of DNA and fix TOP1cc. Tyrosyl-DNA phosphodiesterase 1 (TDP1) is able to eliminate TOP1cc. Thus, TDP1 interferes with the action of topotecan. Poly(ADP-ribose) polymerase 1 (PARP1) is a key regulator of many processes in the cell, such as maintaining the integrity of the genome, regulation of the cell cycle, cell death, and others. PARP1 also controls the repair of TOP1cc. We performed a transcriptomic analysis of wild type and PARP1 knockout HEK293A cells treated with topotecan and TDP1 inhibitor OL9-119 alone and in combination. The largest number of differentially expressed genes (DEGs, about 4000 both up- and down-regulated genes) was found in knockout cells. Topotecan and OL9-119 treatment elicited significantly fewer DEGs in WT cells and negligible DEGs in PARP1-KO cells. A significant part of the changes caused by PARP1-KO affected the synthesis and processing of proteins. Differences under the action of treatment with TOP1 or TDP1 inhibitors alone were found in the signaling pathways for the development of cancer, DNA repair, and the proteasome. The drug combination resulted in DEGs in the ribosome, proteasome, spliceosome, and oxidative phosphorylation pathways.

Mn-based cGAS-STING activation for tumor therapy

Immunotherapy has efficiently revolutionized the treatment of human neoplastic diseases. However, the overall responsive rate of current immunotherapy is still unsatisfactory, benefiting only a small proportion of patients. Therefore, significant attention has been paid to the modulation of tumor microenvironment (TME) for the enhancement of immunotherapy. Interestingly, recent studies have shown that cyclic GMP-AMP synthase-stimulator of interferon gene (cGAS-STING) was initially found as an innate immune sensor to recognize cytoplasmic DNA (such as bacterial, viral, micronuclei, and mitochondrial). It is a promising signaling pathway to activate antitumor immune responses via type I interferon production. Notably, Mn²⁺ was found to be a critical molecule to sensitize the activation of the cGAS-STING pathway for better immunotherapy. This activation led to the development of Mn²⁺-based strategies for tumor immunotherapy via the activation of the cGAS-STING pathway. In this critical review, we aimed to summarize the recent progress of this field, focusing on the following three aspects. First, we briefly introduced the signaling pathway of cGAS-STING activation, and its regulation effect on the antitumor immunity cycle has been discussed. Along with this, several agonists of the cGAS-STING pathway were introduced with their potential as immunotherapeutic drugs. Then, the basic biological functions of Mn²⁺ have been illustrated, focusing on its critical roles in the cGAS-STING pathway activation. Next, we systematically reviewed the Mn²⁺-based strategies for tumor immunotherapy, which can be classified by the methods based on Mn²⁺ alone or Mn²⁺ combined with other therapeutic modalities. We finally speculated the future perspectives of the field and provided rational suggestions to develop better Mn²⁺-based therapeutics.

Potential role for protein kinase D inhibitors in prostate cancer

Protein kinase D (PrKD), a novel serine-threonine kinase, belongs to a family of calcium calmodulin kinases that consists of three isoforms: PrKD1, PrKD2, and PrKD3. The PrKD isoforms play a major role in pathologic processes such as cardiac hypertrophy and cancer progression. The charter member of the family, PrKD1, is the most extensively studied isoform. PrKD play a dual role as both a proto-oncogene and a tumor suppressor depending on the cellular context. The duplicity of PrKD can be highlighted in advanced prostate cancer (PCa) where expression of PrKD1 is suppressed whereas the expressions of PrKD2 and PrKD3 are upregulated to aid in cancer progression. As understanding of the PrKD signaling pathways has been better elucidated, interest has been garnered in the development of PrKD inhibitors. The broad-spectrum kinase inhibitor staurosporine acts as a potent PrKD inhibitor and is the most well-known; however, several other novel and more specific PrKD inhibitors have been developed over the last two decades. While there is tremendous potential for PrKD inhibitors to be used in a clinical setting, none has progressed beyond preclinical trials due to a variety of challenges. In this review, we focus on PrKD signaling in PCa and the potential role of PrKD inhibitors therein, and explore the possible clinical outcomes based on known function and expression of PrKD isoforms at different stages of PCa.

Maslinic acid exerts anticancer effects by targeting cancer hallmarks

BACKGROUND

Natural products have long been regarded as a source of anticancer compounds with low toxicity. Evidence revealed that maslinic acid (MA), a widely distributed pentacyclic triterpene in common foodstuffs, exhibited pronounced inhibitory effects against various cancer cell lines. Most cancer cells thrive by acquiring cancer hallmarks, as coined by Hanahan and Weinberg in 2000 and 2011.

PURPOSE

This represents the first systematic review concerning the anticancer properties of MA as these cancer hallmarks are targeted. It aims to summarize the antineoplastic activities of MA, discuss the diverse mechanisms of action based on the effects of MA exerted on each hallmark.

METHODS

A comprehensive literature search was conducted using the search terms "maslinic," "cancer," "tumor," and "neoplasm," to retrieve articles from the databases MEDLINE, EMBASE, Web of Science, and Scopus published up to September 2022. Study selection was conducted by three reviewers independently from title and abstract screening until full-text evaluation. Data extraction was done by one reviewer and counterchecked by the second reviewer.

RESULTS

Of the 330 articles assessed, 40 papers met the inclusion criteria and revealed that MA inhibited 16 different cancer cell types. MA impacted every cancer hallmark by targeting multiple pathways.

CONCLUSION

This review provides insights regarding the inhibitory effects of MA against various cancers and its remarkable biological properties as a pleiotropic bioactive compound, which encourage further investigations.

Clinical Radiobiology for Radiation Oncology

This chapter is focused on radiobiological aspects at the molecular, cellular, and tissue level which are relevant for the clinical use of ionizing radiation (IR) in cancer therapy. For radiation oncology, it is critical to find a balance, i.e., the therapeutic window, between the probability of tumor control and the probability of side effects caused by radiation injury to the healthy tissues and organs. An overview is given about modern precision radiotherapy (RT) techniques, which allow optimal sparing of healthy tissues. Biological factors determining the width of the therapeutic window are explained. The role of the six typical radiobiological phenomena determining the response of both malignant and normal tissues in the clinic, the 6R’s, which are Reoxygenation, Redistribution, Repopulation, Repair, Radiosensitivity, and Reactivation of the immune system, is discussed. Information is provided on tumor characteristics, for example, tumor type, growth kinetics, hypoxia, aberrant molecular signaling pathways, cancer stem cells and their impact on the response to RT. The role of the tumor microenvironment and microbiota is described and the effects of radiation on the immune system including the abscopal effect phenomenon are outlined. A summary is given on tumor diagnosis, response prediction via biomarkers, genetics, and radiomics, and ways to selectively enhance the RT response in tumors. Furthermore, we describe acute and late normal tissue reactions following exposure to radiation: cellular aspects, tissue kinetics, latency periods, permanent or transient injury, and histopathology. Details are also given on the differential effect on tumor and late responding healthy tissues following fractionated and low dose rate irradiation as well as the effect of whole-body exposure.

Chemical Tools for the Study of DNA Repair

DNA repair enzymes continuously provide surveillance throughout our cells, protecting the enclosed DNA from the damage that is constantly arising from oxidation, alkylating species, and radiation. Members of this enzyme class are intimately linked to pathways controlling cancer and inflammation and are promising targets for diagnostics and future therapies. Their study is benefiting widely from the development of new tools and methods aimed at measuring their activities. Here, we provide an Account of our laboratory's work on developing chemical tools to study DNA repair processes in vitro, as well as in cells and tissues, and what we have learned by applying them.We first outline early work probing how DNA repair enzymes recognize specific forms of damage by use of chemical analogs of the damage with altered shapes and H-bonding abilities. One outcome of this was the development of an unnatural DNA base that is incorporated selectively by polymerase enzymes opposite sites of missing bases (abasic sites) in DNA, a very common form of damage.We then describe strategies for design of fluorescent probes targeted to base excision repair (BER) enzymes; these were built from small synthetic DNAs incorporating fluorescent moieties to engender light-up signals as the enzymatic reaction proceeds. Examples of targets for these DNA probes include UDG, SMUG1, Fpg, OGG1, MutYH, ALKBH2, ALKBH3, MTH1, and NTH1. Several such strategies were successful and were applied both in vitro and in cellular settings; moreover, some were used to discover small-molecule modulators of specific repair enzymes. One of these is the compound SU0268, a potent OGG1 inhibitor that is under investigation in animal models for inhibiting hyperinflammatory responses.To investigate cellular nucleotide sanitation pathways, we designed a series of "two-headed" nucleotides containing a damaged DNA nucleotide at one end and ATP at the other; these were applied to studying the three human sanitation enzymes MTH1, dUTPase, and dITPase, some of which are therapeutic targets. The MTH1 probe (ARGO) was used in collaboration with oncologists to measure the enzyme in tumors as a disease marker and also to develop the first small-molecule activators of the enzyme.We proceed to discuss the development of a "universal" probe of base excision repair processes (UBER), which reacts covalently with abasic site intermediates of base excision repair. UBER probes light up in real time as the reaction occurs, enabling the observation of base excision repair as it occurs in live cells and tissues. UBER probes can also be used in efficient and simple methods for fluorescent labeling of DNA. Finally, we suggest interesting directions for the future of this field in biomedicine and human health.

Suitability of salivary leucocytes to assess DNA repair ability in human biomonitoring studies by the challenge-comet assay

The challenge-comet assay is a simple but effective approach that provides a quantitative and functional determination of DNA repair ability, and allows to monitor the kinetics of repair process. Peripheral blood mononuclear cells (PBMC) are the cells most frequently employed in human biomonitoring studies using the challenge-comet assay, but having a validated alternative of non-invasive biomatrix would be highly convenient for certain population groups and circumstances. The objective of this study was to validate the use of salivary leucocytes in the challenge-comet assay. Leucocytes were isolated from saliva samples and challenged (either in fresh or after cryopreservation) with three genotoxic agents acting by different action mechanisms: bleomycin, methyl methanesulfonate, and ultraviolet radiation. Comet assay was performed just after treatment and at other three additional time points, in order to study repair kinetics. The results obtained demonstrated that saliva leucocytes were as suitable as PBMC for assessing DNA damage of different nature that was efficiently repaired over the evaluated time points, even after 5 months of cryopreservation (after a 24 h stimulation with PHA). Furthermore, a new parameter to determine the efficacy of the repair process, independent of the initial amount of damage induced, is proposed, and recommendations to perform the challenge-comet assay with salivary leucocytes depending on the type of DNA repair to be assessed are suggested. Validation studies are needed to verify whether the method is reproducible and results reliable and comparable among laboratories and studies.

MiR-140 leads to MRE11 downregulation and ameliorates oxaliplatin treatment and therapy response in colorectal cancer patients

Cancer therapy failure is a fundamental challenge in cancer treatment. One of the most common reasons for therapy failure is the development of acquired resistance of cancer cells. DNA-damaging agents are frequently used in first-line chemotherapy regimens and DNA damage response, and DNA repair pathways are significantly involved in the mechanisms of chemoresistance. MRE11, a part of the MRN complex involved in double-strand break (DSB) repair, is connected to colorectal cancer (CRC) patients’ prognosis. Our previous results showed that single-nucleotide polymorphisms (SNPs) in the 3′ untranslated region (3′UTR) microRNA (miRNA) binding sites of MRE11 gene are associated with decreased cancer risk but with shorter survival of CRC patients, which implies the role of miRNA regulation in CRC. The therapy of colorectal cancer utilizes oxaliplatin (oxalato(trans-l-1,2-diaminocyclohexane)platinum), which is often compromised by chemoresistance development. There is, therefore, a crucial clinical need to understand the cellular processes associated with drug resistance and improve treatment responses by applying efficient combination therapies. The main aim of this study was to investigate the effect of miRNAs on the oxaliplatin therapy response of CRC patients. By the in silico analysis, miR-140 was predicted to target MRE11 and modulate CRC prognosis. The lower expression of miR-140 was associated with the metastatic phenotype (p < 0.05) and poor progression-free survival (odds ratio (OR) = 0.4, p < 0.05). In the in vitro analysis, we used miRNA mimics to increase the level of miR-140 in the CRC cell line. This resulted in decreased proliferation of CRC cells (p < 0.05). Increased levels of miR-140 also led to increased sensitivity of cancer cells to oxaliplatin (p < 0.05) and to the accumulation of DNA damage. Our results, both in vitro and in vivo, suggest that miR-140 may act as a tumor suppressor and plays an important role in DSB DNA repair and, consequently, CRC therapy response.

Recent advances and limitations of mTOR inhibitors in the treatment of cancer

The PI3K-Akt-mechanistic (formerly mammalian) target of the rapamycin (mTOR) signaling pathway is important in a variety of biological activities, including cellular proliferation, survival, metabolism, autophagy, and immunity. Abnormal PI3K-Akt-mTOR signalling activation can promote transformation by creating a cellular environment conducive to it. Deregulation of such a system in terms of genetic mutations and amplification has been related to several human cancers. Consequently, mTOR has been recognized as a key target for the treatment of cancer, especially for treating cancers with elevated mTOR signaling due to genetic or metabolic disorders. In vitro and in vivo, rapamycin which is an immunosuppressant agent actively suppresses the activity of mTOR and reduces cancer cell growth. As a result, various sirolimus-derived compounds have now been established as therapies for cancer, and now these medications are being investigated in clinical studies. In this updated review, we discuss the usage of sirolimus-derived compounds and other drugs in several preclinical or clinical studies as well as explain some of the challenges involved in targeting mTOR for treating various human cancers.

DNA damage repair gene signature model for predicting prognosis and chemotherapy outcomes in lung squamous cell carcinoma

BACKGROUND

Lung squamous cell carcinoma (LUSC) is prone to metastasis and likely to develop resistance to chemotherapeutic drugs. DNA repair has been reported to be involved in the progression and chemoresistance of LUSC. However, the relationship between LUSC patient prognosis and DNA damage repair genes is still unclear.

METHODS

The clinical information of LUSC patients and tumour gene expression level data were downloaded from the TCGA database. Unsupervised clustering and Cox regression were performed to obtain molecular subtypes and prognosis-related significant genes based on a list including 150 DNA damage repair genes downloaded from the GSEA database. The coefficients determined by the multivariate Cox regression analysis and the expression level of prognosis-related DNA damage repair genes were employed to calculate the risk score, which divided LUSC patients into two groups: the high-risk group and the low-risk group. Immune viability, overall survival, and anticarcinogen sensitivity analyses of the two groups of LUSC patients were performed by Kaplan-Meier analysis with the log rank test, ssGSEA and the pRRophetic package in R software. A time-dependent ROC curve was applied to compare the survival prediction ability of the risk score, which was used to construct a survival prediction model by multivariate Cox regression. The prediction model was used to build a nomogram, the discriminative ability of which was confirmed by C-index assessment, and its calibration was validated by calibration curve analysis. Differentially expressed DNA damage repair genes in LUSC patient tissues were retrieved by the Wilcoxon test and validated by qRT-PCR and IHC.

RESULT

LUSC patients were separated into two clusters based on molecular subtypes, of which Cluster 2 was associated with worse overall survival. A prognostic prediction model for LUSC patients was constructed and validated, and a risk score calculated based on the expression levels of ten DNA damage repair genes was employed. The clinical utility was evaluated by drug sensitivity and immune filtration analyses. Thirteen-one genes were upregulated in LUSC patient samples, and we selected the top four genes that were validated by RT-PCR and IHC.

CONCLUSION

We established a novel prognostic model based on DNA damage repair gene expression that can be used to predict therapeutic efficacy in LUSC patients.

Integrated multi-omics analysis identifies ENY2 as a predictor of recurrence and a regulator of telomere maintenance in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and has a high recurrence rate. Accurate prediction of recurrence risk is urgently required for tailoring personalized treatment programs for individual HCC patients in advance. In this study, we analyzed a gene expression dataset from an HCC cohort with 247 samples and identified five genes including ENY2, GPAA1, NDUFA4L2, NEDD9, and NRP1 as the variables for the prediction of HCC recurrence, especially the early recurrence. The Cox model and risks score were validated in two public HCC cohorts (GSE76427 and The Cancer Genome Atlas (TCGA)) and one cohort from Huashan Hospital, which included a total of 641 samples. Moreover, the multivariate Cox regression analysis revealed that the risk score could serve as an independent prognostic factor in the prediction of HCC recurrence. In addition, we found that ENY2, GPAA1, and NDUFA4L2 were significantly upregulated in HCC of the two validation cohorts, and ENY2 had significantly higher expression levels than another four genes in malignant cells, suggesting that ENY2 might play key roles in malignant cells. The cell line analysis revealed that ENY2 could promote cell cycle progression, cell proliferation, migration, and invasion. The functional analysis of the genes correlated with ENY2 revealed that ENY2 might be involved in telomere maintenance, one of the fundamental hallmarks of cancer. In conclusion, our data indicate that ENY2 may regulate the malignant phenotypes of HCC via activating telomere maintenance.

The Relationship between Exposure to Airborne Particulate and DNA Adducts in Blood Cells in an Urban Population of Subjects with an Unhealthy Body Mass Index

Bulky DNA adducts are a combined sign of aromatic chemical exposure, as well as an individual's ability to metabolically activate carcinogens and repair DNA damage. The present study aims to investigate the association between PM exposure and DNA adducts in blood cells, in a population of 196 adults with an unhealthy BMI (≥25). For each subject, a DNA sample was obtained for quantification of DNA adducts by sensitive³²P post-labelling methods. Individual PM₁₀ exposure was derived from daily mean concentrations measured by single monitors in the study area and then assigned to each subject by calculating the mean of the 30 days (short-term exposure), and of the 365 (long-term exposure) preceding enrolment. Multivariable linear regression models were used to study the association between PM₁₀ and DNA adducts. The majority of analysed samples had bulky DNA adducts, with an average value of 3.7 ± 1.6 (mean ± SD). Overall, the findings of the linear univariate and multiple linear regression showed an inverse association between long-term PM₁₀ exposure and adduct levels; this unexpected result might be since the population consists of subjects with an unhealthy BMI, which might show an atypical reaction to airborne urban pollutants; a hermetic response which happens when small amounts of pollutants are present. Pollutants can linger for a long time in the adipose tissue of obese persons, contributing to an increase in oxidative DNA damage, inflammation, and thrombosis when exposure is sustained.

A pooled analysis of molecular epidemiological studies on modulation of DNA repair by host factors

Levels of DNA damage represent the dynamics between damage formation and removal. Therefore, to better interpret human biomonitoring studies with DNA damage endpoints, an individual's ability to recognize and properly remove DNA damage should be characterized. Relatively few studies have included DNA repair as a biomarker and therefore, assembling and analyzing a pooled database of studies with data on base excision repair (BER) was one of the goals of hCOMET (EU-COST CA15132). A group of approximately 1911 individuals, was gathered from 8 laboratories which run population studies with the comet-based in vitro DNA repair assay. BER incision activity data were normalized and subsequently correlated with various host factors. BER was found to be significantly higher in women. Although it is generally accepted that age is inversely related to DNA repair, no overall effect of age was found, but sex differences were most pronounced in the oldest quartile (>61 years). No effect of smoking or occupational exposures was found. A body mass index (BMI) above 25 kg/m² was related to higher levels of BER. However, when BMI exceeded 35 kg/m², repair incision activity was significantly lower. Finally, higher BER incision activity was related to lower levels of DNA damage detected by the comet assay in combination with formamidopyrimidine DNA glycosylase (Fpg), which is in line with the fact that oxidatively damaged DNA is repaired by BER. These data indicate that BER plays a role in modulating the steady-state level of DNA damage that is detected in molecular epidemiological studies and should therefore be considered as a parallel endpoint in future studies.

Low-Cost Genetic and Clinical Predictors of Response and Toxicity of Platinum-Based Chemotherapy in Advanced Non-Small Cell Lung Cancer

Background

This study aimed to evaluate for the first time whether certain genetic and clinical factors could serve as minimally invasive predictors of survival and toxicity to platinum-based chemotherapy in advanced lung adenocarcinoma.

Methods

The study included 121 advanced lung adenocarcinoma patients treated with platinum-based dublets until progression or unacceptable toxicity. Response was evaluated using standard radiological methods and toxicity graded according to the Common Terminology Criteria for Adverse Events (CTCAE) v5.0. Genotyping was performed using PCR-RFLP. Statistical significance was set at P < .05.

Results

No significant influence of the examined polymorphisms on the occurrence of high-grade toxicity was detected. However, TP53 72Pro allele carriers were more prone to nausea (P = .037) and thrombocytopenia (P = .051). Anemia and neuropathy occurred more frequently in XRCC1 399Arg allele carriers (Pearson χ2 test, P = .025 and P = .004 respectively). RAD51 135CC carriers were significantly more prone to neutropenia (P = .027).

Conclusions

A set of easily determined genetic and clinical predictors of survival and specific toxicity profiles of platinum-based chemotherapy in advanced lung adenocarcinoma were determined in this study, which might be useful for the construction of population-specific, time- and cost-efficient prognostic and predictive algorithms.

Human Satellite III long non-coding RNA imparts survival benefits to cancer cells

Long non-coding RNAs (lncRNAs) are heterogeneous group of transcripts that lack coding potential and have essential roles in gene regulations. Recent days have seen an increasing association of non-coding RNAs with human diseases, especially cancers. One interesting group of non-coding RNAs strongly linked to cancers are heterochromatic repetitive Satellite RNAs. Satellite RNAs are transcribed from pericentromeric heterochromatic region of the human chromosomes. Satellite II RNA, most extensively studied, is upregulated in wide variety of epithelial cancer. Similarly, alpha satellite is over expressed in BRCA1- deficient tumors. Though much is known about alpha satellites and SatII repeats, little is known about Satellite III (SatIII) lncRNAs in human cancers. SatIII repeats, though transcriptionally silent in normal conditions is actively transcribed under condition of stress, mainly heat shock. In the present study, we show that colon and breast cancer cells aberrantly transcribes SatIII, in a Heat shock factor I (HSF1)-independent manner. Our study also reveals that, overexpression of SatIII RNA favours cancer cell survival by overriding chemo drug-induced cell death. Interestingly, knockdown of SatIII sensitizes cells towards chemotherapeutic drugs. This sensitization is possibly mediated by restoration of p53 protein expression that facilitates cell death. Heat shock however helps SatIII to continue with its pro-cell survival function. Our results, therefore suggest SatIII to be an important regulator of human cancers. Induction of SatIII is not only a response to the oncogenic stress but also facilitates cancer progression by a distinct pathway that is different from heat stress pathway. This article is protected by copyright. All rights reserved.

MicroRNAs Regulate Cell Cycle and Cell Death Pathways in Glioblastoma

Glioblastoma (GBM), a grade IV brain tumor, is known for its heterogenicity and its resistance to the current treatment regimen. Over the last few decades, a significant amount of new molecular and genetic findings has been reported regarding factors contributing to GBM’s development into a lethal phenotype and its overall poor prognosis. MicroRNA (miRNAs) are small non-coding sequences of RNA that regulate and influence the expression of multiple genes. Many research findings have highlighted the importance of miRNAs in facilitating and controlling normal biological functions, including cell differentiation, proliferation, and apoptosis. Furthermore, miRNAs’ ability to initiate and promote cancer development, directly or indirectly, has been shown in many types of cancer. There is a clear association between alteration in miRNAs expression in GBM’s ability to escape apoptosis, proliferation, and resistance to treatment. Further, miRNAs regulate the already altered pathways in GBM, including P53, RB, and PI3K-AKT pathways. Furthermore, miRNAs also contribute to autophagy at multiple stages. In this review, we summarize the functions of miRNAs in GBM pathways linked to dysregulation of cell cycle control, apoptosis and resistance to treatment, and the possible use of miRNAs in clinical settings as treatment and prediction biomarkers.

The INPP4B paradox: Like PTEN, but different

Cancer is a complex and heterogeneous disease marked by the dysregulation of cancer driver genes historically classified as oncogenes or tumour suppressors according to their ability to promote or inhibit tumour development and growth, respectively. Certain genes display both oncogenic and tumour suppressor functions depending on the biological context, and as such have been termed dual-role cancer driver genes. However, because of their context-dependent behaviour, the tumourigenic mechanism of many dual-role genes is elusive and remains a significant knowledge gap in our effort to understand and treat cancer. Inositol polyphosphate 4-phosphatase type II (INPP4B) is an emerging dual-role cancer driver gene, primarily known for its role as a negative regulator of the phosphoinositide 3-kinase (PI3K)/AKT signalling pathway. In response to growth factor stimulation, class I PI3K generates PtdIns(3,4,5)P₃ at the plasma membrane. PtdIns(3,4,5)P₃ can be hydrolysed by inositol polyphosphate 5-phosphatases to generate PtdIns(3,4)P₂, which, together with PtdIns(3,4,5)P₃, facilitates the activation of AKT to promote cell proliferation, survival, migration, and metabolism. Phosphatase and tensin homology on chromosome 10 (PTEN) and INPP4B are dual-specificity phosphatases that hydrolyse PtdIns(3,4,5)P₃ and PtdIns(3,4)P₂, respectively, and thus negatively regulate PI3K/AKT signalling. PTEN is a bona fide tumour suppressor that is frequently lost in human tumours. INPP4B was initially characterised as a tumour suppressor akin to PTEN, and has been implicated as such in a number of cancers, including prostate, thyroid, and basal-like breast cancers. However, evidence has since emerged revealing INPP4B as a paradoxical oncogene in several malignancies, with increased INPP4B expression reported in AML, melanoma and colon cancers among others. Although the tumour suppressive function of INPP4B has been mostly ascribed to its ability to negatively regulate PI3K/AKT signalling, its oncogenic function remains less clear, with proposed mechanisms including promotion of PtdIns(3)P-dependent SGK3 signalling, inhibition of PTEN-dependent AKT activation, and enhancing DNA repair mechanisms to confer chemoresistance. Nevertheless, research is ongoing to identify the factors that dictate the tumourigenic output of INPP4B in different human cancers. In this review we discuss the dualistic role that INPP4B plays in the context of cancer development, progression and treatment, drawing comparisons to PTEN to explore how their similarities and, importantly, their differences may account for their diverging roles in tumourigenesis.

Airborne particulate matter induces oxidative damage, DNA adduct formation and alterations in DNA repair pathways

Air pollution, which includes particulate matter (PM), is classified in group 1 as a carcinogen to humans by the International Agency for Research in Cancer. Specifically, PM exposure has been associated with lung cancer in patients living in highly polluted cities. The precise mechanism by which PM is linked to cancer has not been completely described, and the genotoxicity induced by PM exposure plays a relevant role in cell damage. In this review, we aimed to analyze the types of DNA damage and alterations in DNA repair pathways induced by PM exposure, from both epidemiological and toxicological studies, to comprehend the contribution of PM exposure to carcinogenesis. Scientific evidence supports that PM exposure mainly causes oxidative stress by reactive oxygen species (ROS) and the formation of DNA adducts, specifically by polycyclic aromatic hydrocarbons (PAH). PM exposure also induces double-strand breaks (DSBs) and deregulates the expression of some proteins in DNA repair pathways, precisely, base and nucleotide excision repairs and homologous repair. Furthermore, specific polymorphisms of DNA repair genes could lead to an adverse response in subjects exposed to PM. Nevertheless, information about the effects of PM on DNA repair pathways is still limited, and it has not been possible to conclude which pathways are the most affected by exposure to PM or if DNA damage is repaired properly. Therefore, deepening the study of genotoxic damage and alterations of DNA repair pathways is needed for a more precise understanding of the carcinogenic mechanism of PM.

The biological and pharmacological connections between diabetes and various types of cancer

Diabetes and cancer incidence have risen tremendously over the years. Additionally, both cancer and diabetes share numerous risks, such as overweight, inactive lifestyles, older age, and smoking. Numerous methods have been suggested to connect obesity and diabetes to cancer advancements, such as increasing insulin/ Insulin-like growth factor I (IGF-1) signaling, lipid and glucose uptake and metabolism, shifts in the cytokine, chemokine, and adipokine profile also variations in the adipose tissue immediately adjacent to cancer spots. Diabetes has been found to have a complicated cancer-causing mechanism involving excessive reactive oxygen species (ROS) production, loss of critical macromolecules, chronic inflammation, and delayed repair, all of which contribute to carcinogenesis. Diabetes-associated epithelial-to-mesenchymal transition and endothelial-to-mesenchymal transition lead to the formation of cancer-associated fibroblasts in tumors by enabling tumor cells to extravasate via the endothelium and epithelium. This study aims to describe the correlation between diabetes and cancer, as well as summarize the molecular connections and shared pathways such as sex hormones, hyperglycemia, inflammation, insulin axis, metabolic symbiosis, and endoplasmic reticulum (ER) stress that exist between them.

Understanding the Radiobiology of Vestibular Schwannomas to Overcome Radiation Resistance

Vestibular schwannomas (VS) are benign tumors arising from cranial nerve VIII that account for 8-10% of all intracranial tumors and are the most common tumors of the cerebellopontine angle. These tumors are typically managed with observation, radiation therapy, or microsurgical resection. Of the VS that are irradiated, there is a subset of tumors that are radioresistant and continue to grow; the mechanisms behind this phenomenon are not fully understood. In this review, the authors summarize how radiation causes cellular and DNA injury that can activate (1) checkpoints in the cell cycle to initiate cell cycle arrest and DNA repair and (2) key events that lead to cell death. In addition, we discuss the current knowledge of VS radiobiology and how it may contribute to clinical outcomes. A better understanding of VS radiobiology can help optimize existing treatment protocols and lead to new therapies to overcome radioresistance.

Canonical Signaling Pathways in Melanoma

Melanoma is the most lethal type of skin cancer, originating from the uncontrolled proliferation of melanocytes. The transformation of normal melanocytes into malignant tumor cells has been a focus of research seeking to better understand melanoma's pathogenesis and develop new therapeutic targets. Over the past few decades, a conglomeration of studies has pinpointed several driver mutations and their associated signaling pathways. In this review, we summarize the key signaling pathways and the driver mutations involved in melanoma tumorigenesis and also discuss the potential underlying mechanisms.

Beta-Genus Human Papillomavirus 8 E6 Destabilizes the Host Genome by Promoting p300 Degradation

The beta genus of human papillomaviruses infects cutaneous keratinocytes. Their replication depends on actively proliferating cells and, thus, they conflict with the cellular response to the DNA damage frequently encountered by these cells. This review focus on one of these viruses (HPV8) that counters the cellular response to damaged DNA and mitotic errors by expressing a protein (HPV8 E6) that destabilizes a histone acetyltransferase, p300. The loss of p300 results in broad dysregulation of cell signaling that decreases genome stability. In addition to discussing phenotypes caused by p300 destabilization, the review contains a discussion of the extent to which E6 from other β-HPVs destabilizes p300, and provides a discussion on dissecting HPV8 E6 biology using mutants.

Therapeutic Potential of PARP Inhibitors in the Treatment of Gastrointestinal Cancers

Gastrointestinal (GI) malignancies are a major global health burden, with high mortality rates. The identification of novel therapeutic strategies is crucial to improve treatment and survival of patients. The poly (ADP-ribose) polymerase (PARP) enzymes involved in the DNA damage response (DDR) play major roles in the development, progression and treatment response of cancer, with PARP inhibitors (PARPi) currently used in the clinic for breast, ovarian, fallopian, primary peritoneal, pancreatic and prostate cancers with deficiencies in homologous recombination (HR) DNA repair. This article examines the current evidence for the role of the DDR PARP enzymes (PARP1, 2, 3 and 4) in the development, progression and treatment response of GI cancers. Furthermore, we discuss the role of HR status as a predictive biomarker of PARPi efficacy in GI cancer patients and examine the pre-clinical and clinical evidence for PARPi and cytotoxic therapy combination strategies in GI cancer. We also include an analysis of the genomic and transcriptomic landscape of the DDR PARP genes and key HR genes (BRCA1, BRCA2, ATM, RAD51, MRE11, PALB2) in GI patient tumours (n = 1744) using publicly available datasets to identify patients that may benefit from PARPi therapeutic approaches.

The influence of an enamine usnic acid derivative (a tyrosyl-DNA phosphodiesterase 1 inhibitor) on the therapeutic effect of topotecan against transplanted tumors in vivo

Tyrosyl-DNA phosphodiesterase 1 (Tdp1) is a repair enzyme for 3'-end DNA lesions, predominantly stalled DNA-topoisomerase 1 (Top1) cleavage complexes. Tdp1 is a promising target for anticancer therapy based on DNA damage caused by Top1 poisoning. Earlier, we have reported about usnic acid enamine derivatives that are Tdp1 inhibitors sensitizing tumor cells to the action of Top1 poison (Zakharenko in J Nat Prod 79:2961-2967, 2016). In the present work, we showed a sensitizing effect of an enamine derivative of usnic acid (when administered intragastrically) on Lewis lung carcinoma in mice in combination with topotecan (TPT, Top1 poison used in the clinic). In the presence of the usnic acid derivative, both the volume of the primary tumor and the number of metastases significantly diminished. The absence of acute toxicity of this compound was demonstrated, as was the importance of the method of its administration for the manifestation of the sensitizing properties.

Benzo[a]pyrene diol epoxide-induced transformed cells identify the significance of hsa_circ_0051488, a ERCC1-derived circular RNA in pulmonary squamous cell carcinoma

ERCC1 is a gene for repairing DNA damage whose function is related to carcinogenic-induced tumorigenesis and the effectiveness of platinum therapies. Circular RNAs (circRNAs) are products of posttranscriptional regulation with pleiotropic effects on the pathogenesis of lung cancer. We aim to identify that specific circRNAs derived from ERCC1 can regulate key biological processes involved in the development of lung cancer. We performed bioinformatics analysis, in vitro experiments, and analyzed clinical samples, to determine the biological features of a certain ERCC1-derived circRNA termed as hsa_circ_0051488 in benzo[a]pyrene diol epoxide-induced malignant transformed cell and lung cancer cell. The well-established model of transformed cells provided an ideal platform for analyzing the molecular characteristics of this circRNA in the malignant transformation of lung epithelial cell, which supports that hsa_circ_0051488 functions in the onset and growth of lung squamous cell carcinoma (LUSC). Further analysis indicates that the absence of hsa_circ_0051488 promoted the proliferation of cells with the malignant phenotype. Extensive experiments confirm that hsa_circ_0051488 is present in the cytoplasm and functioned as a competing endogenous RNA. In particular, hsa_circ_0051488 binds to mir-6717-5p, thereby modulating the expression of SATB2 gene, a lung cancer suppressor. Furthermore, our in silico experiments indicate that SATB2 can inhibit multiple tumor pathways and its expression positively correlated with the tumor suppressor gene CRMP1. These findings suggest a possible regulatory mechanism of hsa_circ_0051488 in LUSC, and that the newly discovered hsa_circ_0051488/miR-6717-5p/SATB2 axis may be a potential route for therapeutic intervention of LUSC.

From kidney injury to kidney cancer

Epidemiologic studies document strong associations between acute or chronic kidney injury and kidney tumors. However, whether these associations are linked by causation, and in which direction, is unclear. Accumulating data from basic and clinical research now shed light on this issue and prompt us to propose a new pathophysiological concept with immanent implications in the management of patients with kidney disease and patients with kidney tumors. As a central paradigm, this review proposes the mechanisms of kidney damage and repair that are active during acute kidney injury but also during persistent injuries in chronic kidney disease as triggers of DNA damage, promoting the expansion of (pre-)malignant cell clones. As renal progenitors have been identified by different studies as the cell of origin for several benign and malignant kidney tumors, we discuss how the different types of kidney tumors relate to renal progenitors at specific sites of injury and to germline or somatic mutations in distinct signaling pathways. We explain how known risk factors for kidney cancer rather represent risk factors for kidney injury as an upstream cause of cancer. Finally, we propose a new role for nephrologists in kidney cancer (i.e., the primary and secondary prevention and treatment of kidney injury to reduce incidence, prevalence, and recurrence of kidney cancer).

STING Agonists as Cancer Therapeutics

The interrogation of intrinsic and adaptive resistance to cancer immunotherapy has identified lack of antigen presentation and type I interferon signaling as biomarkers of non-T-cell-inflamed tumors and clinical progression. A myriad of pre-clinical studies have implicated the cGAS/stimulator of interferon genes (STING) pathway, a cytosolic DNA-sensing pathway that drives activation of type I interferons and other inflammatory cytokines, in the host immune response against tumors. The STING pathway is also increasingly understood to have other anti-tumor functions such as modulation of the vasculature and augmentation of adaptive immunity via the support of tertiary lymphoid structure development. Many natural and synthetic STING agonists have entered clinical development with the first generation of intra-tumor delivered cyclic dinucleotides demonstrating safety but only modest systemic activity. The development of more potent and selective STING agonists as well as novel delivery systems that would allow for sustained inflammation in the tumor microenvironment could potentially augment response rates to current immunotherapy approaches and overcome acquired resistance. In this review, we will focus on the latest developments in STING-targeted therapies and provide an update on the clinical development and application of STING agonists administered alone, or in combination with immune checkpoint blockade or other approaches.

STINGing the Tumor Microenvironment to Promote Therapeutic Tertiary Lymphoid Structure Development

Tertiary lymphoid structures (TLS), also known as ectopic lymphoid structures (ELS) or tertiary lymphoid organs (TLO), represent a unique subset of lymphoid tissues noted for their architectural similarity to lymph nodes, but which conditionally form in peripheral tissues in a milieu of sustained inflammation. TLS serve as regional sites for induction and expansion of the host B and T cell repertoires via an operational paradigm involving mature dendritic cells (DC) and specialized endothelial cells (i.e. high endothelial venules; HEV) in a process directed by TLS-associated cytokines and chemokines. Recent clinical correlations have been reported for the presence of TLS within tumor biopsies with overall patient survival and responsiveness to interventional immunotherapy. Hence, therapeutic strategies to conditionally reinforce TLS formation within the tumor microenvironment (TME) via the targeting of DC, vascular endothelial cells (VEC) and local cytokine/chemokine profiles are actively being developed and tested in translational tumor models and early phase clinical trials. In this regard, a subset of agents that promote tumor vascular normalization (VN) have been observed to coordinately support the development of a pro-inflammatory TME, maturation of DC and VEC, local production of TLS-inducing cytokines and chemokines, and therapeutic TLS formation. This mini-review will focus on STING agonists, which were originally developed as anti-angiogenic agents, but which have recently been shown to be effective in promoting VN and TLS formation within the therapeutic TME. Future application of these drugs in combination immunotherapy approaches for greater therapeutic efficacy is further discussed.

A study of deregulated MMR pathways and anticancer potential of curcuma derivatives using computational approach

Plant derived products have steadily gained momentum in treatment of cancer over the past decades. Curcuma and its derivatives, in particular, have diverse medicinal properties including anticancer potential with proven safety as supported by numerous in vivo and in vitro studies. A defective Mis-Match Repair (MMR) is implicated in solid tumors but its role in haematologic malignancies is not keenly studied and the current literature suggests that it is limited. Nonetheless, there are multiple pathways interjecting the mismatch repair proteins in haematologic cancers that may have a direct or indirect implication in progression of the disease. Here, through computational analysis, we target proteins that are involved in rewiring of multiple signaling cascades via altered expression in cancer using various curcuma derivatives (Curcuma longa L. and Curcuma caesia Roxb.) which in turn, profoundly controls MMR protein function. These biomolecules were screened to identify their efficacy on selected targets (in blood-related cancers); aberrations of which adversely impacted mismatch repair machinery. The study revealed that of the 536 compounds screened, six of them may have the potential to regulate the expression of identified targets and thus revive the MMR function preventing genomic instability. These results reveal that there may be potential plant derived biomolecules that may have anticancer properties against the tumors driven by deregulated MMR-pathways.

Cancer as a prospective sequela of long COVID-19

As the spread of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) continues to surge worldwide, our knowledge of coronavirus disease 2019 (COVID‐19) is rapidly expanding. Although most COVID‐19 patients recover within weeks of symptom onset, some experience lingering symptoms that last for months (“long COVID‐19”). Early reports of COVID‐19 sequelae, including cardiovascular, pulmonary, and neurological conditions, have raised concerns about the long‐term effects of COVID‐19, especially in hard‐hit communities. It is becoming increasingly evident that cancer patients are more susceptible to SARS‐CoV‐2 infection and are at a higher risk of severe COVID‐19 than the general population. Nevertheless, whether long COVID‐19 increases the risk of cancer in those with no prior malignancies, remains unclear. Given, the disproportionate impact of the disease on the African American community, yet another unanswered question is whether racial disparities are to be expected in COVID‐19 sequelae. Herein, we propose that long COVID‐19 may predispose recovered patients to cancer development and accelerate cancer progression. This hypothesis is based on growing evidence of the ability of SARS‐CoV‐2 to modulate oncogenic pathways, promote chronic low‐grade inflammation, and cause tissue damage. Comprehensive studies are urgently required to elucidate the effects of long COVID‐19 on cancer susceptibility.

Importance of Bioactive Substances in Sheep's Milk in Human Health

Sheep's milk is an important source of bioactive substances that have health-promoting functions for the body. The valuable composition of sheep's milk is due to the high content of fatty acids, immunoglobulins, proteins, hormones, vitamins and minerals. Many biopeptides found in milk have antibacterial, antiviral and anti-inflammatory properties. The bioactive substances of sheep's milk also show anticancer properties. Sheep's milk, thanks to its content of CLA and orotic acid, prevents the occurrence of type 2 diabetes, Alzheimer's disease and cancer. Sheep's milk, as a product rich in bioactive substances, can be used as a medical aid to support the body in the fight against neurological and cancer diseases.

The functional roles of TCA cycle metabolites in cancer

The tricarboxylic acid cycle (TCA cycle) has been known for decades as a hub for generating cellular energy and precursors for biosynthetic pathways. Several cancers harbor mutations that affect the integrity of this cycle, mostly at the levels of isocitrate dehydrogenase (IDH), succinate dehydrogenase (SDH), and fumarate hydratase (FH). This results in dysregulation in the production of TCA cycle metabolites and is probably implicated in cancer initiation. By modulating cellular activities, including metabolism and signaling, TCA cycle intermediates are able to impact the processes of cancer development and progression. In this review, we discuss the functional roles of the TCA cycle intermediates in suppressing or promoting the progression of cancers. A further understanding of TCA metabolites' roles and molecular mechanisms in oncogenesis would prompt developing novel metabolite-based cancer therapy in the future.