circPVT1 and PVT1/AKT3 show a role in cell proliferation, apoptosis, and tumor subtype-definition in small cell lung cancer

circFOXK2 Stabilizes STMN1 mRNA via PABPC1 to Promote the Progression of NSCLC

BACKGROUND

Lung cancer has a notably high incidence and mortality rate, and understanding its occurrence and development is crucial for effective treatment. Circular RNA is closely associated with tumor progression, playing a role in tumorigenesis and development by regulating gene expression and influencing cell proliferation and apoptosis. This study aims to explore the circFOXK2 role in NSCLC occurrence and development and to elucidate its underlying mechanisms.

METHODS

qRT-PCR and Western Blot analyzed the expressions of circFOXK2, STMN1, and PABPCA in NSCLC cell lines, as well as their relationships. The roles of circFOXK2 and STMN1 in the proliferation, invasion, and migration of NSCLC cells were assessed through CCK8, EDU, and Transwell experiments. RNA pulldown assays with mass spectrometry elucidated the RNA-binding proteins of circFOXK2. Subcutaneous tumorigenesis and tail vein lung metastasis experiments analyzed the impact of circFOXK2 on tumor growth and metastasis in vivo.

RESULTS

In this study, we identified circFOXK2, which is significantly overexpressed in NSCLC, through bioinformatics screening. Elevated levels of circFOXK2 enhance the growth and metastasis of NSCLC cells. Furthermore, through experiments such as co-IP and mass spectrometry, we found that circFOXK2 interacts with PABPC1 to form a complex, which correlates positively with the progression and metastasis of tumors. Simultaneously, the circFOXK2/PABPC1 complex increases the stability of STMN1 mRNA, thereby promoting the transcription and translation of STMN1. Our experimental results indicate that the oncogenic effect of circFOXK2 requires the assistance of STMN1.

CONCLUSIONS

In summary, we have demonstrated the significant role of circFOXK2/PABPC1 in regulating STMN1 expression in NSCLC.

Osteosarcoma in a ceRNET perspective

Osteosarcoma (OS) is the most prevalent and fatal type of bone tumor. It is characterized by great heterogeneity of genomic aberrations, mutated genes, and cell types contribution, making therapy and patients management particularly challenging. A unifying picture of molecular mechanisms underlying the disease could help to transform those challenges into opportunities.This review deeply explores the occurrence in OS of large-scale RNA regulatory networks, denominated "competing endogenous RNA network" (ceRNET), wherein different RNA biotypes, such as long non-coding RNAs, circular RNAs and mRNAs can functionally interact each other by competitively binding to shared microRNAs. Here, we discuss how the unbalancing of any network component can derail the entire circuit, driving OS onset and progression by impacting on cell proliferation, migration, invasion, tumor growth and metastasis, and even chemotherapeutic resistance, as distilled from many studies. Intriguingly, the aberrant expression of the networks components in OS cells can be triggered also by the surroundings, through cytokines and vesicles, with their bioactive cargo of proteins and non-coding RNAs, highlighting the relevance of tumor microenvironment. A comprehensive picture of RNA regulatory networks underlying OS could pave the way for the development of innovative RNA-targeted and RNA-based therapies and new diagnostic tools, also in the perspective of precision oncology.

Aggressive systemic mastocytosis with the co-occurrence of PRKG2::PDGFRB, KAT6A::NCOA2, and RXRA::NOTCH1 fusion transcripts and a heterozygous RUNX1 frameshift mutation

Systemic mastocytosis (SM) is a myeloproliferative neoplasm displaying abnormal mast cell proliferation. It is subdivided into different forms, including aggressive systemic mastocytosis (ASM) and systemic mastocytosis with an associated hematologic neoplasm (SM-AHN). Oncogenic genetic alterations include point mutations, mainly the KIT D816V, conferring poor prognosis and therapy resistance, and fusion genes, with those involving PDGFRA/PDGFRB as the most recurrent events. We here describe an ASM case negative to the KIT D816V and JAK2 V617F alterations but showing a RUNX1 frameshift heterozygous mutation and the co-occurrence of three fusion transcripts. The first one, PRKG2::PDGFRB, was generated by a balanced t(4;5)(q24;q32) translocation as the sole abnormality. Other two novel chimeras, KAT6A::NCOA2 and RXRA::NOTCH1, originated from cryptic intra-chromosomal abnormalities. The patient rapidly evolved towards SM-AHN, characterized by the persistence of the PRKG2::PDGFRB chimera, due to the presence of an extra copy of the der(5)t(4;5)(q24;q34) chromosome and an increase in the RUNX1 mutation allelic frequency. The results indicated that the transcriptional landscape and the mutational profile of SM deserve attention to predict the evolution and prognosis of this complex disease, whose classification criteria are still a matter of debate.

Long non-coding RNA (lncRNA) PVT1 in drug resistance of cancers: Focus on pathological mechanisms

According to estimates, cancer will be the leading cause of death globally in 2022, accounting for 9.6 million deaths. At present, the three main therapeutic modalities utilized to treat cancer are radiation therapy, chemotherapy, and surgery. However, during treatment, tumor cells resistant to chemotherapy may arise. Drug resistance remains a major oppose since it often leads to therapeutic failure. Furthermore, the term "acquired drug resistance" describes the situation where tumor cells already display drug resistance before undergoing chemotherapy. However, little is still known about the basic mechanisms underlying chemotherapy-induced drug resistance. The development of new technologies and bioinformatics has led to the discovery of additional genes associated with drug resistance. Long noncoding RNA plasmacytoma variant translocation 1 (PVT1) has been linked to an increased risk of cancer, according to a growing body of research. Apart from biological functions associated with cell division, development, pluripotency, and cell cycle, lncRNA PVT1 contributes significantly to the regulation of various aspects of genome function, such as transcription, splicing, and epigenetics. The article will address the mechanism by which lncRNA PVT1 influences drug resistance in cancer cells.

PVT1 lncRNA in lung cancer: A key player in tumorigenesis and therapeutic opportunities

The lncRNA PVT1 has emerged as a pivotal component in the intricate landscape of cancer pathogenesis, particularly in lung cancer. PVT1, situated in the 8q24 chromosomal region, has garnered attention for its aberrant expression patterns in lung cancer, correlating with tumor progression, metastasis, and poor prognosis. Numerous studies have unveiled the diverse mechanisms PVT1 contributes to lung cancer pathogenesis. It modulates critical pathways, such as cell proliferation, apoptosis evasion, angiogenesis, and epithelial-mesenchymal transition. PVT1's interactions with other molecules, including microRNAs and proteins, amplify its oncogenic influence. Recent advancements in genomic and epigenetic analyses have also illuminated the intricate regulatory networks that govern PVT1 expression. Understanding PVT1's complex involvement in lung cancer holds substantial clinical implications. Targeting PVT1 presents a promising avenue for developing novel diagnostic biomarkers and therapeutic interventions. This abstract encapsulates the expanding knowledge regarding the oncogenic role of PVT1 in lung cancer, underscoring the significance of further research to unravel its complete mechanistic landscape and exploit its potential for improved patient outcomes.

PD-1/PD-L1 Inhibitors plus Chemotherapy Versus Chemotherapy Alone for Resectable Non-Small Cell Lung Cancer: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: The benefit of adding programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) inhibitors to the treatment of early-stage non-small cell lung cancer (NSCLC), both neoadjuvant therapy (NAT) and adjuvant therapy (AT), is not yet fully elucidated. Methods: We searched PubMed, Embase, and Cochrane databases for randomized controlled trials (RCT) that investigated PD-1/PD-L1 inhibitors plus chemotherapy for resectable stage NSCLC. We computed hazard ratios (HRs) or odds ratios (ORs) for binary endpoints, with 95% confidence intervals (CIs). Results: A total of seven RCTs comprising 3915 patients with resectable stage NSCLC were randomized to chemotherapy with or without PD-1/PD-L1 inhibitors as NAT or AT. As NAT, the PD-1/PD-L1 inhibitors plus chemotherapy group demonstrated significantly improved overall survival (HR 0.66; 95% CI 0.51-0.86) and event-free survival (HR 0.53; 95% CI 0.43-0.67) compared with the chemotherapy alone group. There was a significant increase in favor of the PD-1/PD-L1 inhibitors plus chemotherapy group for major pathological response (OR 6.40; 95% CI 3.86-10.61) and pathological complete response (OR 8.82; 95% CI 4.51-17.26). Meanwhile, as AT, disease-free survival was significant in favor of the PD-1/PD-L1 inhibitors plus chemotherapy group (HR 0.78; 95% CI 0.69-0.90). Conclusions: In this comprehensive systematic review and meta-analysis of RCTs, the incorporation of PD-1/PD-L1 inhibitors alongside chemotherapy offers a promising prospect for reshaping the established treatment paradigms for patients diagnosed with resectable stages of NSCLC. Moreover, our analyses support that neoadjuvant administration with these agents should be encouraged, in light of the fact that it was associated with an increased survival and pathological response, at the expense of a manageable safety profile.

Advancements in Focal Amplification Detection in Tumor/Liquid Biopsies and Emerging Clinical Applications

Focal amplifications (FAs) are crucial in cancer research due to their significant diagnostic, prognostic, and therapeutic implications. FAs manifest in various forms, such as episomes, double minute chromosomes, and homogeneously staining regions, arising through different mechanisms and mainly contributing to cancer cell heterogeneity, the leading cause of drug resistance in therapy. Numerous wet-lab, mainly FISH, PCR-based assays, next-generation sequencing, and bioinformatics approaches have been set up to detect FAs, unravel the internal structure of amplicons, assess their chromatin compaction status, and investigate the transcriptional landscape associated with their occurrence in cancer cells. Most of them are tailored for tumor samples, even at the single-cell level. Conversely, very limited approaches have been set up to detect FAs in liquid biopsies. This evidence suggests the need to improve these non-invasive investigations for early tumor detection, monitoring disease progression, and evaluating treatment response. Despite the potential therapeutic implications of FAs, such as, for example, the use of HER2-specific compounds for patients with ERBB2 amplification, challenges remain, including developing selective and effective FA-targeting agents and understanding the molecular mechanisms underlying FA maintenance and replication. This review details a state-of-the-art of FA investigation, with a particular focus on liquid biopsies and single-cell approaches in tumor samples, emphasizing their potential to revolutionize the future diagnosis, prognosis, and treatment of cancer patients.