ATR-binding lncRNA ScaRNA2 promotes cancer resistance through facilitating efficient DNA end resection during homologous recombination repair

Radiotherapy-immunity lncRNA model predicts lung adenocarcinoma prognosis and treatment outcome and distinguishes between hot and cold tumors

BACKGROUND

There are many prognostic markers for lung adenocarcinoma (LUAD). However, studies on the prognosis of LUAD by radiotherapy immune-related long noncoding RNAs (lncRNAs) are extremely rare.

METHODS

We have compiled 1121 radiotherapy susceptibility differential genes and 6195 immune-related genes. After that, we screened radiotherapy-immunity lncRNAs associated with proliferation by co-expression, univariate, least absolute shrinkage selection operator regression (LASSO), and multivariate analysis of variance. Finally, we constructed a prognostic model based on 6 lncRNAs, and verified the accuracy of the predictive model by ROC and C index. In addition, we used the constructed scoring model to analyze the model's association with the characteristics of immune cell infiltration, immune checkpoint and drug sensitivity. Finally, the whole sample was divided into 2 clusters to further distinguish hot and cold tumors.

RESULTS

We constructed a risk score model built on 6 prognostically relevant lncRNAs. Patients were categorized into high-risk and low-risk patients based on median scores in the Train group. We found that people in the high-risk group had a lower survival rate than those in the low-risk group. However, those in the high-risk group were more sensitive to chemotherapy, targeted drugs and also more sensitive to immunotherapy drugs. Based on the line graphs of T, N, Age, Stage and Risk, the corresponding scores can be summed up to visualize the survival rate of patients at 1, 3 and 5 years. Gene set enrichment analysis (GSEA) suggested that radiotherapy-immunity-related lncRNA might be related to pathways such as cell cycle, T cell receptor signaling pathway. It is noteworthy that in our study, cluster 1 was considered to be a hot tumor more sensitive to immunotherapy.

CONCLUSION

In summary, we constructed a risk score model built on six radiosensitivity and immune-related lncRNAs, which is expected to be a potential predictive biomarker for radiosensitivity and LUAD prognosis.

Reversing regulatory safeguards: Targeting the ATR pathway to overcome PARP inhibitor resistance

The development of poly (ADP-ribose) polymerase inhibitors (PARPis) is widely considered a therapeutic milestone in the management of BRCA1/2-deficient malignancies. Since a growing number of cancer treatment guidelines include PARPis, the inevitably emerging PARPi resistance becomes a serious limitation that must be addressed. Targeting the DNA damage response signaling kinase, ATR (ataxia telangiectasia and rad3-related serine/threonine kinase), activated in response to PARPi-induced replication stress, represents a promising approach in fighting PARPi-resistant cancers. The success of this combination therapy in preclinical models has inspired efforts to translate its potential through extensive clinical research and clinical trials. However, the available clinical evidence suggests that PARPi/ATRi combinations have yet to reach their anticipated therapeutic potential. In this review, we summarize work elucidating mechanisms underpinning the effectiveness of ATRi in fighting PARPi resistance and review translational studies reporting efficacy in different types of cancer. Finally, we discuss potential biomarkers of patient selection for customized combinations of PARPi/ATRi treatments.

LncRNA LINC01664 promotes cancer resistance through facilitating homologous recombination-mediated DNA repair

The intracellular responses to DNA double-strand breaks (DSB) repair are crucial for genomic stability and play an essential role in cancer resistance. In addition to canonical DSB repair proteins, long non-coding RNAs (lncRNAs) have been found to be involved in this sophisticated network. In the present study, we performed a loss-of-function screen for a customized siRNA Premix Library to identify lncRNAs that participate in homologous recombination (HR) process. Among the candidates, we identified LINC01664 as a novel lncRNA required for HR repair. Furthermore, LINC01664 knockdown significantly increased the sensitivity of cancer cells to DNA damage agents such as ionizing radiation and genotoxic drugs. Mechanistically, LINC01664 interacted with Sirt1 promoter and then activated Sirt1 transcription, which contributed to HR-mediated DNA damage repair. In summary, our findings revealed a new mechanism of LINC01664 in DNA damage repair, providing evidence for a potential therapeutic strategy for eliminating the treatment bottlenecks caused by cancer resistance to chemotherapy and radiotherapy.

Advances in the mechanism of small nucleolar RNA and its role in DNA damage response

Small nucleolar RNAs (snoRNAs) were previously regarded as a class of functionally conserved housekeeping genes, primarily involved in the regulation of ribosome biogenesis by ribosomal RNA (rRNA) modification. However, some of them are involved in several biological processes via complex molecular mechanisms. DNA damage response (DDR) is a conserved mechanism for maintaining genomic stability to prevent the occurrence of various human diseases. It has recently been revealed that snoRNAs are involved in DDR at multiple levels, indicating their relevant theoretical and clinical significance in this field. The present review systematically addresses four main points, including the biosynthesis and classification of snoRNAs, the mechanisms through which snoRNAs regulate target molecules, snoRNAs in the process of DDR, and the significance of snoRNA in disease diagnosis and treatment. It focuses on the potential functions of snoRNAs in DDR to help in the discovery of the roles of snoRNAs in maintaining genome stability and pathological processes.

LncRNAs: Emerging biomarkers and therapeutic targets in rectal cancer

According to findings, long non-coding RNAs (lncRNAs) have an important function in the onset and growth of various cancers, including rectal cancer (RC). RC offers unique issues in terms of diagnosis, treatment, and results, needing a full understanding of the cellular mechanisms that cause it to develop. This thorough study digs into the various functions that lncRNAs perform in RC, giving views into their multiple roles as well as possible therapeutic consequences. The function of lncRNAs in RC cell proliferation, apoptosis, migratory and infiltrating capacities, epithelial-mesenchymal shift, and therapy tolerance are discussed. Various lncRNA regulatory roles are investigated in depth, yielding information on their effect on essential cell functions such as angiogenesis, death, immunity, and growth. Systemic lncRNAs are currently acknowledged as potential indications for the initial stages of identification of cancer, with the ability to diagnose as well as forecast. Besides adding to their diagnostic utility, lncRNAs offer therapeutic opportunities as actors, contributing to the expanding landscape of cancer research. Moreover, the investigation looks into the assessment and predictive utility of lncRNAs as RC markers. The article also offers insight into lncRNAs as chemoresistance and drug resistance facilitators in the setting of RC.