The p53 family reaches the final frontier: the variegated regulation of the dark matter of the genome by the p53 family in cancer

Long non-coding RNAs play an important regulatory role in tumorigenesis and tumor progression through aerobic glycolysis

Compared to normal cells, cancer cells generate ATP mainly through aerobic glycolysis, which promotes tumorigenesis and tumor progression. Long non-coding RNAs (LncRNAs) are a class of transcripts longer than 200 nucleotides with little or without evident protein-encoding function. LncRNAs are involved in the ten hallmarks of cancer, interestingly, they are also closely associated with aerobic glycolysis. However, the mechanism of this process is non-transparent to date. Demonstrating the mechanism of lncRNAs regulating tumorigenesis and tumor progression through aerobic glycolysis is particularly critical for cancer therapy, and may provide novel therapeutic targets or strategies in cancer treatment. In this review, we discuss the role of lncRNAs and aerobic glycolysis in tumorigenesis and tumor progression, and further explore their interaction, in hope to provide a novel therapeutic target for cancer treatment.

Identification of the Potential Correlation between Tumor Protein 73 and Head and Neck Squamous Cell Carcinoma

Background

Head and neck squamous cell carcinomas (HNSC) are common malignant tumors with a high occurrence and poor prognosis. Tumor protein P73 (TP73) plays an integral role in a wide range of human malignancies, but its gene expression profile, prognostic value, and potential mechanisms in HNSC remain to be comprehensively explored.

Objective

This research aimed to elucidate the potential relationship between TP73 and HNSC through bioinformatics analysis.

Methods

The Cancer Genome Atlas (TCGA) database was queried to investigate the regulatory role of TP73 in HNSC. The survival probabilities linked to TP73 mRNA were determined via the Kaplan-Meier analysis using R packages. Subsequently, the association of TP73 with several clinical subgroups and immunological subtypes was studied using a cohort from the TCGA-HNSC. Functional analyses were used to identify the potential signaling pathways enriched by the correlated genes of TP73. The relationship between TP73 and immunological aspects, including immune cells, immune inhibitor genes, immune stimulator genes, and tumor immune microenvironment, were investigated.

Results

This study showed that the protein and mRNA levels of TP73 in HNSC patients were significantly higher than those in normal tissues. Elevated TP73 expression was related to a better survival outcome in HNSC patients. The TP73 gene was an independent prognostic factor for overall survival in HNSC samples. TP73 was mainly involved in DNA replication, ribosome, apoptosis, mismatch repair, and folate biosynthesis. TP73 was found to be positively correlated with the majority of tumor infiltrating immune cells and immunoinhibitory genes in HNSC.

Conclusions

Integrative bioinformatics and statistical analyses displayed that TP73 might serve as a novel marker for the diagnosis and prognosis of HNSC. TP73 modulates immune cells in the tumor microenvironment of HNSC patients, thereby bearing significance for HNSC immunotherapy.

[Research Advances of EGFR-TP53 Co-mutation in Advanced Non-small Cell Lung Cancer]

With the rapid development and wide application of next generation sequencing (NGS) technology, a series of researches have revealed that concurrent genetic alterations play an important role in the response and resistance of epidermal growth factor receptor (EGFR)-mutant NSCLC to EGFR-tyrosine kinase inhibitor (TKI). Besides, TP53 mutation is the most common co-mutation gene in EGFR-mutant NSCLC, which has been proved to confer a worse prognosis in EGFR-mutated patients treated with first, second and third generation of EGFR-TKIs. Currently, it is still being explored how to select the best treatment strategies for patients with concomitant presence of TP53 mutation in EGFR-mutant NSCLC. Here, we review the literature on recent research progress of TP53 concurrent mutation in EGFR-mutant advanced NSCLC.
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Pan-cancer analysis reveals TAp63-regulated oncogenic lncRNAs that promote cancer progression through AKT activation

The most frequent genetic alterations across multiple human cancers are mutations in TP53 and the activation of the PI3K/AKT pathway, two events crucial for cancer progression. Mutations in TP53 lead to the inhibition of the tumour and metastasis suppressor TAp63, a p53 family member. By performing a mouse-human cross species analysis between the TAp63 metastatic mammary adenocarcinoma mouse model and models of human breast cancer progression, we identified two TAp63-regulated oncogenic lncRNAs, TROLL-2 and TROLL-3. Further, using a pan-cancer analysis of human cancers and multiple mouse models of tumour progression, we revealed that these two lncRNAs induce the activation of AKT to promote cancer progression by regulating the nuclear to cytoplasmic translocation of their effector, WDR26, via the shuttling protein NOLC1. Our data provide preclinical rationale for the implementation of these lncRNAs and WDR26 as therapeutic targets for the treatment of human tumours dependent upon mutant TP53 and/or the PI3K/AKT pathway.

KRAB domain of ZFP568 disrupts TRIM28-mediated abnormal interactions in cancer cells

Interactions of KRAB (Krüppel-associated box)-associated protein KAP1 [also known as TRIM28 (tripartite motif containing protein 28)] with DNA-binding KRAB zinc finger (KRAB-ZF) proteins silence many transposable elements during embryogenesis. However, in some cancers, TRIM28 is upregulated and interacts with different partners, many of which are transcription regulators such as EZH2 in MCF7 cells, to form abnormal repressive or activating complexes that lead to misregulation of genes. We ask whether a KRAB domain-the TRIM28 interaction domain present in native binding partners of TRIM28 that mediate repression of transposable elements-could be used as a tool molecule to disrupt aberrant TRIM28 complexes. Expression of KRAB domain containing fragments from a KRAB-ZF protein (ZFP568) in MCF7 cells, without the DNA-binding zinc fingers, inhibited TRIM28-EZH2 interactions and caused degradation of both TRIM28 and EZH2 proteins as well as other components of the EZH2-associated polycomb repressor 2 complex. In consequence, the product of EZH2 enzymatic activity, trimethylation of histone H3 lysine 27 level, was significantly reduced. The expression of a synthetic KRAB domain significantly inhibits the growth of breast cancer cells (MCF7) but has no effect on normal (immortalized) human mammary epithelial cells (MCF10a). Further, we found that TRIM28 is a positive regulator of TRIM24 protein levels, as observed previously in prostate cancer cells, and expression of the KRAB domain also lowered TRIM24 protein. Importantly, reduction of TRIM24 levels, by treatment with either the KRAB domain or a small-molecule degrader targeted to TRIM24, is accompanied by an elevated level of tumor suppressor p53. Taken together, this study reveals a novel mechanism for a TRIM28-associated protein stability network and establishes TRIM28 as a potential therapeutic target in cancers where TRIM28 is elevated. Finally, we discuss a potential mechanism of KRAB-ZF gene expression controlled by a regulatory feedback loop of TRIM28-KRAB.