p63 and p73 in tumor suppression and promotion

p53 amyloid pathology is correlated with higher cancer grade irrespective of the mutant or wild-type form

p53 (also known as TP53) mutation and amyloid formation are long associated with cancer pathogenesis; however, the direct demonstration of the link between p53 amyloid load and cancer progression is lacking. Using multi-disciplinary techniques and 59 tissues (53 oral and stomach cancer tumor tissue samples from Indian individuals with cancer and six non-cancer oral and stomach tissue samples), we showed that p53 amyloid load and cancer grades are highly correlated. Furthermore, next-generation sequencing (NGS) data suggest that not only mutant p53 (e.g. single-nucleotide variants, deletions, and insertions) but wild-type p53 also formed amyloids either in the nucleus (50%) and/or in the cytoplasm in most cancer tissues. Interestingly, in all these cancer tissues, p53 displays a loss of DNA-binding and transcriptional activities, suggesting that the level of amyloid load correlates with the degree of loss and an increase in cancer grades. The p53 amyloids also sequester higher amounts of the related p63 and p73 (also known as TP63 and TP73, respectively) protein in higher-grade tumor tissues. The data suggest p53 misfolding and/or aggregation, and subsequent amyloid formation, lead to loss of the tumor-suppressive function and the gain of oncogenic function, aggravation of which might determine the cancer grade.

Genome-Wide Identification of Autophagy Prognostic Signature in Pancreatic Cancer

Background:

Autophagy plays a vital role in cancer development. However, there is currently no comprehensive study regarding the effects of autophagy-related genes (ARGs) on pancreatic cancer prognosis. Thus, this study aimed to establish an autophagy-related signature for predicting the prognosis of patients with pancreatic cancer.

Methods:

We identified and validated differentially-expressed ARGs using data from The Cancer Genome Atlas (TCGA) database, Genotype-Tissue Expression project (GTEx) and Expression Omnibus (GEO) database. We performed Cox proportional hazards regression analysis on the differentially-expressed ARGs to develop an autophagy-related signature. We tested the expression of these genes through western blotting and verified their prognostic values through gene expression profiling and interactive analyses (GEPIA).

Results:

We identified a total of 21 differentially-expressed ARGs and screened 4 OS-related ARGs (TP63, RAB24, APOL1, and PTK6). Both the training and validation sets showed that the autophagy-related signature was more accurate than the Tumor Node Metastasis (TNM) staging system. Moreover, the western blotting result showed that the expression of TP63, APOL1, and PTK6 was high, whereas that of RAB24 was low in cancer tissues.

Conclusion:

This 4-ARG signature might potentially help in providing personalized therapy to patients with cancer.

A Newly Defined Pyroptosis-Related Gene Signature for the Prognosis of Bladder Cancer

BACKGROUND

Bladder cancer (BC), as the most common urinary system tumor type and the main cause of tumor-related death, has an unsatisfactory prognosis. In recent years, related literature has proposed that cell pyroptosis is an inflammatory form of programmed cell death. However, in BC, the relationship between the expression of pyroptosis-related genes and the prognosis has not been elucidated.

METHODS

We got the RNA sequencing data from TCGA and GEO datasets. Fifty-two pyroptosis-related genes were extracted for further explore. Then, we compared the gene expression levels between the normal bladder and BC tissues. After that, we develop and validate a pyroptosis-related gene prognostic model and made following functional enrichment analysis and single-sample gene set enrichment analysis of the differentially expressed genes between the high- and low-risk groups.

RESULTS

Twenty-nine differentially expressed genes (DEGs) were found between normal and tumor tissues. Based on the median score calculated by the risk score formula from 8 pyroptosis-related genes, 414 patients were equally divided into low- and high-risk subgroups. The survival probability of BC patients in the high-risk group was significantly lower than that in the low-risk group (P < 0.001). Through multivariate analysis, our risk score is an independent factor predicting OS in BC patients. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis show that high-risk populations are rich in immune-related genes and have a decreased immune status. All the above results have been externally verified from GEO cohort.

CONCLUSION

Pyroptosis-related genes are closely related to tumor immunity and are a potential prognostic tool for predicting BCs.

ΔNp63 to TAp63 expression ratio as a potential molecular marker for cervical cancer prognosis

p63 is a transcription factor p53 family. Two major isoforms of p63, TAp63 with transactivation (TA) domain and ΔNp63 with truncated TA domain, have been reported to play opposing roles either in tumor suppression or oncogenic function. Little is known about the association of these two isoforms of p63 in the carcinogenesis of cervical cancer. In this study, the mRNA expression levels of TAp63 and ΔNp63 in 40 normal, 30 low-grade squamous intraepithelial lesions (LSIL), 38 high-grade squamous intraepithelial lesions (HSIL), and 52 cervical cancer formalin-fixed paraffin-embedded tissues were examined using quantitative reverse transcription polymerase chain reaction (RT-qPCR). We analyzed the association between the ΔNp63 and ΔN/TAp63 mRNA expression ratio and clinicopathological parameters and compared disease-specific survival of each ΔNp63 mRNA expression and ΔN/TAp63 mRNA expression ratio. The ΔN/TAp63 mRNA expression ratio in cervical cancer showed higher sensitivity than the mRNA expression levels of ΔNp63 (52.0% vs 44.2%). The level of ΔN/TAp63 mRNA expression ratio in precancerous LSIL and HSIL was higher than in normal tissues (P = 0.01 and P = 0.003) and lower than in cervical cancer tissues (P = 0.03 and P = 0.02). Besides, the positive ΔN/TAp63 mRNA expression ratio was associated with bulky tumor size and high expression of Ki-67, the proliferation marker, in cervical cancer (P = 0.04 and P = 0.02). The cervical cancer patients with the positive ΔN/TAp63 mRNA expression ratio showed worse survival compared to those who with the negative expression ratio of ΔN/TAp63 (HR = 5.7, 95% CI: 1.6–19.9). In conclusion, the balance of TAp63 and ΔNp63 is closely related to the carcinogenesis of cervical cancer. The ΔN/TAp63 mRNA expression ratio could be useful as a diagnostic and prognostic marker of cervical cancer.

Canine mammary tumors as a model for human disease

Animal models for examining human breast cancer (HBC) carcinogenesis have been extensively studied and proposed. With the recent advent of immunotherapy, significant attention has been focused on the dog as a model for human cancer. Dogs develop mammary tumors and other cancer types spontaneously with an intact immune system, which exhibit a number of clinical and molecular similarities to HBC. In addition to the spontaneous tumor presentation, the clinical similarities between human and canine mammary tumors (CMT) include the age at onset, hormonal etiology and course of the diseases. Furthermore, factors that affect the disease outcome, including tumor size, stage and lymph node invasion, are similar in HBC and CMT. Similarly, the molecular characteristics of steroid receptor, epidermal growth factor, proliferation marker, metalloproteinase and cyclooxygenase expression, and the mutation of the p53 tumor suppressor gene in CMT, mimic HBC. Furthermore, ductal carcinomas in situ in human and canine mammary glands are particularly similar in their pathological, molecular and visual characteristics. These CMT characteristics and their similarities to HBC indicate that the dog could be an excellent model for the study of human disease. These similarities are discussed in detail in the present review, and are compared with the in vitro and other in vivo animal models available.

Identification of a novel microRNA-mRNA regulatory biomodule in human prostate cancer

Our recent study identified a list of differentially expressed microRNAs (miRNAs) in human prostate cancer (PCa) tissues compared to adjacent benign prostate tissues. In the current study, to identify the crucial miRNA-mRNA regulatory biomodule involved into prostate carcinogenesis based on the previous miRNA expression profile in PCa, we proposed an integrated systematic approach which combined miRNA-mediated gene expression regulatory network analysis, experimental validations in vitro and in vivo, as well as clinical significance evaluation. As a result, the CCND1-RNASEL-CDKN1A-TP73-MDM2-UBE2I axis was identified as a bottleneck in the miRNA-mediated gene expression regulatory network of PCa according to network topological analysis. The direct binding relationship between TP73 and PCa downregulated miR-193a-5p, and the direct binding relationship between UBE2I and PCa upregulated miR-188-5p were both experimentally validated. In addition, miR-193a-5p had a more significant regulatory effect on the tumor promoter isoform of TP73-deltaNp73 than on the tumor suppressive isoform of TP73-TAp73. Importantly, the deregulation of either the miR-193a-5p-TP73 or miR-188-5p-UBE2I axes was significantly associated with aggressive progression and poor prognosis in PCa patients. Gain- and loss-of-function experiments showed that miR-193a-5p efficiently inhibited in vitro PCa cell proliferation, migration, and invasion, and in vivo tumor growth, and markedly induced PCa cell apoptosis via regulating TP73 with a corresponding suppression of the CCND1-RNASEL-CDKN1A-MDM2 axis. In contrast, miR-188-5p exerted its tumor promoter roles through targeting UBE2I with a subsequent activation of the CCND1-RNASEL-CDKN1A-MDM2 axis. Taken together, this integrated analysis revealed the potential roles of the miR-193a-5p/TP73 and miR-188-5p/UBE2i negative regulation pairs in PCa. In addition to the significant clinical relevance, miR-193a-5p- and miR-188-5p-regulated CCND1-RNASEL-CDKN1A-TP73-MDM2-UBE2I signaling may be a novel regulatory biomodule in prostate carcinogenesis.

p53 family members - important messengers in cell death signaling in photodynamic therapy of cancer?

TP53 is one of the genes most frequently inactivated in cancers. Mutations in TP53 gene are linked to worse prognosis and shorter overall survival of cancer patients. TP53 encodes a critical tumor suppressor, which dictates cell fate decisions upon stress stimuli. As a sensor of cellular stress, p53 is a relevant messenger of cell death signaling in ROS-driven photodynamic therapy (PDT) of cancer. The significant role of p53 in response to PDT has been reported for several clinically approved photosensitizers. Multiple reports described that wild-type p53 contributes to cell killing upon photodynamic therapy with clinically approved photosensitizers but the mechanism is still not fully understood. This work outlines the diverse functions of p53 family members in cancer cells' susceptibility and resistance to PDT. In summary p53 and p53 family members are emerging as important mediators of cell death signaling in photodynamic therapy of cancer, however the mechanism of cell death provoked during PDT might differ depending on the tissue type and the photosensitizer applied.