Current developments of targeting the p53 signaling pathway for cancer treatment

Butein inhibits cancer cell growth by rescuing the wild-type thermal stability of mutant p53

p53 is a transcription factor that activates the expression of various genes involved in the maintenance of genomic stability, and more than 50% of cancers harbor inactivating p53 mutations, which are indicative of highly aggressive cancer and poor prognosis. Pharmacological targeting of mutant p53 to restore the wild-type p53 tumor-suppressing function is a promising strategy for cancer therapy. In this study, we identified a small molecule, Butein, that reactivates mutant p53 activity in tumor cells harboring the R175H or R273H mutation. Butein restored wild-type-like conformation and DNA-binding ability in HT29 and SK-BR-3 cells harboring mutant p53-R175H and mutant p53-R273H, respectively. Moreover, Butein enabled the transactivation of p53 target genes and decreased the interactions of Hsp90 with mutant p53-R175H and mutant p53-R273H proteins, while Hsp90 overexpression reversed targeted p53 gene activation. In addition, Butein induced thermal stabilization of wild-type p53, mutant p53-R273H and mutant p53-R175H, as determined via CETSA. From docking study, we further proved that Butein binding to p53 stabilized the DNA-binding loop-sheet-helix motif of mutant p53-R175H and regulated its DNA-binding activity via an allosteric mechanism, conferring wild-type-like the DNA-binding activity of mutant p53. Collectively, the data suggest that Butein is a potential antitumor agent that restores p53 function in cancers harboring mutant p53-R273H or mutant p53-R175H. SIGNIFICANCE: Butein restores the ability of mutant p53 to bind DNA by reversing its transition to the Loop3 (L3) state, endows p53 mutants with thermal stability and re-establishes their transcriptional activity to induce cancer cell death.

miRNAs as potential game-changers in renal cell carcinoma: Future clinical and medicinal uses

Renal cell carcinoma (RCC) has the highest mortality rate of all genitourinary cancers, and its prevalence has grown over time. While RCC can be surgically treated and recurrence is only probable in a tiny proportion of patients, early diagnosis is crucial. Mutations in a large number of oncogenes and tumor suppressor genes contribute to pathway dysregulation in RCC. MicroRNAs (miRNAs) have considerable promise as biomarkers for detecting cancer due to their special combination of properties. Several miRNAs have been proposed as a diagnostic or monitoring tool for RCC based on their presence in the blood or urine. Moreover, the expression profile of particular miRNAs has been associated with the response to chemotherapy, immunotherapy, or targeted therapeutic options like sunitinib. The goal of this review is to go over the development, spread, and evolution of RCC. Also, we emphasize the outcomes of studies that examined the use of miRNAs in RCC patients as biomarkers, therapeutic targets, or modulators of responsiveness to treatment modalities.

Molecular Spectroscopy Evidence of 1,3,5-Tris(4-carboxyphenyl)benzene Binding to DNA: Anticancer Potential along with the Comparative Binding Profile of Intercalation via Modeling Studies

One of medicinal chemistry's top priorities is the discovery of new molecules with anticancer potential. Compounds that interact with DNA are an intriguing family of chemotherapeutic medications used to treat cancer. Studies in this area have uncovered a plethora of potential anticancer medicines, such as groove binding, alkylating, and intercalator compounds. The anticancer activity of DNA intercalators (molecules that intercalate between DNA base pairs) has drawn special interest. The current study investigated the promising anticancer drug 1,3,5-Tris(4-carboxyphenyl)benzene (H3BTB) against breast and cervical cancer cell lines. In addition, 1,3,5-Tris(4-carboxyphenyl)benzene binds to DNA by groove binding. The binding of H3BTB to DNA was found to be significant which unwinds the DNA helix. Considerable electrostatic and non-electrostatic contributions were present in the binding's free energy. The cytotoxic potential of H3BTB is effectively demonstrated by the computational study outcomes, which include molecular docking and molecular dynamics (MD) simulations. The minor groove binding for the H3BTB-DNA complex is supported by molecular docking research. This study will promote empirical investigation into the synthesis of metallic and non-metallic H3BTB derivatives and their potential use as bioactive molecules for the treatment of cancer.

Targeting Mitochondrial Metabolic Reprogramming as a Potential Approach for Cancer Therapy

Abnormal energy metabolism is a characteristic of tumor cells, and mitochondria are important components of tumor metabolic reprogramming. Mitochondria have gradually received the attention of scientists due to their important functions, such as providing chemical energy, producing substrates for tumor anabolism, controlling REDOX and calcium homeostasis, participating in the regulation of transcription, and controlling cell death. Based on the concept of reprogramming mitochondrial metabolism, a range of drugs have been developed to target the mitochondria. In this review, we discuss the current progress in mitochondrial metabolic reprogramming and summarized the corresponding treatment options. Finally, we propose mitochondrial inner membrane transporters as new and feasible therapeutic targets.

Mutant P53 in the formation and progression of the tumor microenvironment: Friend or foe

TP53 is the most frequently mutated gene in human cancer. It encodes the tumor suppressor protein p53, which suppresses tumorigenesis by acting as a critical transcription factor that can induce the expression of many genes controlling a plethora of fundamental cellular processes, including cell cycle progression, survival, apoptosis, and DNA repair. Missense mutations are the most frequent type of mutations in the TP53 gene. While these can have variable effects, they typically impair p53 function in a dominant-negative manner, thereby altering intra-cellular signaling pathways and promoting cancer development. Additionally, it is becoming increasingly apparent that p53 mutations also have non-cell autonomous effects that influence the tumor microenvironment (TME). The TME is a complex and heterogeneous milieu composed of both malignant and non-malignant cells, including cancer-associated fibroblasts (CAFs), adipocytes, pericytes, different immune cell types, such as tumor-associated macrophages (TAMs) and T and B lymphocytes, as well as lymphatic and blood vessels and extracellular matrix (ECM). Recently, a large body of evidence has demonstrated that various types of p53 mutations directly affect TME. They fine-tune the inflammatory TME and cell fate reprogramming, which affect cancer progression. Notably, re-educating the p53 signaling pathway in the TME may be an effective therapeutic strategy in combating cancer. Therefore, it is timely to here review the recent advances in our understanding of how TP53 mutations impact the fate of cancer cells by reshaping the TME.

Construction of Ovarian Cancer Prognostic Model Based on the Investigation of Ferroptosis-Related lncRNA

(1) Background: Ovarian cancer (OV) has the high mortality rate among gynecological cancers worldwide. Inefficient early diagnosis and prognostic prediction of OV leads to poor survival in most patients. OV is associated with ferroptosis, an iron-dependent form of cell death. Ferroptosis, believed to be regulated by long non-coding RNAs (lncRNAs), may have potential applications in anti-cancer treatments. In this study, we aimed to identify ferroptosis-related lncRNA signatures and develop a novel model for predicting OV prognosis. (2) Methods: We downloaded data from The Cancer Genome Atlas (TCGA), Genotype-Tissue Expression, and Gene Expression Omnibus (GEO) databases. Prognostic lncRNAs were screened by least absolute shrinkage and selection operator (LASSO)-Cox regression analysis, and a prognostic model was constructed. The model's predictive ability was evaluated by Kaplan-Meier (KM) survival analysis and receiver operating characteristic (ROC) curves. The expression levels of these lncRNAs included in the model were examined in normal and OV cell lines using quantitative reverse transcriptase polymerase chain reaction. (3) Results: We constructed an 18 lncRNA prognostic prediction model for OV based on ferroptosis-related lncRNAs from TCGA patient samples. This model was validated using TCGA and GEO patient samples. KM analysis showed that the prognostic model was able to significantly distinguish between high- and low-risk groups, corresponding to worse and better prognoses. Based on the ROC curves, our model shows stronger prediction precision compared with other traditional clinical factors. Immune cell infiltration, immune checkpoint expression levels, and Tumor Immune Dysfunction and Exclusion analyses are also insightful for OV immunotherapy. (4) Conclusions: The prognostic model constructed in this study has potential for improving our understanding of ferroptosis-related lncRNAs and providing a new tool for prognosis and immune response prediction in patients with OV.

Radiogenomic markers enable risk stratification and inference of mutational pathway states in head and neck cancer

PURPOSE

Head and neck squamous cell carcinomas (HNSCCs) are a molecularly, histologically, and clinically heterogeneous set of tumors originating from the mucosal epithelium of the oral cavity, pharynx, and larynx. This heterogeneous nature of HNSCC is one of the main contributing factors to the lack of prognostic markers for personalized treatment. The aim of this study was to develop and identify multi-omics markers capable of improved risk stratification in this highly heterogeneous patient population.

METHODS

In this retrospective study, we approached this issue by establishing radiogenomics markers to identify high-risk individuals in a cohort of 127 HNSCC patients. Hybrid in vivo imaging and whole-exome sequencing were employed to identify quantitative imaging markers as well as genetic markers on pathway-level prognostic in HNSCC. We investigated the deductibility of the prognostic genetic markers using anatomical and metabolic imaging using positron emission tomography combined with computed tomography. Moreover, we used statistical and machine learning modeling to investigate whether a multi-omics approach can be used to derive prognostic markers for HNSCC.

RESULTS

Radiogenomic analysis revealed a significant influence of genetic pathway alterations on imaging markers. A highly prognostic radiogenomic marker based on cellular senescence was identified. Furthermore, the radiogenomic biomarkers designed in this study vastly outperformed the prognostic value of markers derived from genetics and imaging alone.

CONCLUSION

Using the identified markers, a clinically meaningful stratification of patients is possible, guiding the identification of high-risk patients and potentially aiding in the development of effective targeted therapies.

Identifying Tumor-Associated Genes from Bilayer Networks of DNA Methylation Sites and RNAs

Network theory has attracted much attention from the biological community because of its high efficacy in identifying tumor-associated genes. However, most researchers have focused on single networks of single omics, which have less predictive power. With the available multiomics data, multilayer networks can now be used in molecular research. In this study, we achieved this with the construction of a bilayer network of DNA methylation sites and RNAs. We applied the network model to five types of tumor data to identify key genes associated with tumors. Compared with the single network, the proposed bilayer network resulted in more tumor-associated DNA methylation sites and genes, which we verified with prognostic and KEGG enrichment analyses.

To investigate the prognostic factors of stage Ⅰ-Ⅱ gastric cancer based on P53 mutation and tumor budding

BACKGROUND

P53 is a tumor suppressor and genome guardian factor, and tumor budding is a key link in tumor metastasis. The purpose of this study was to investigate P53 mutation and tumor budding in stage Ⅰ-Ⅱ gastric cancer, to explore the correlation with clinicopathological features, and to reveal the independent prognostic factors of gastric cancer.

METHODS

The data of 588 patients with stage Ⅰ-Ⅱ gastric cancer who underwent radical surgical resection from April 2015 to December 2016 in the Fourth Hospital of Hebei Medical University were retrospectively analyzed and followed up. Immunohistochemistry Envision method was used to conduct P53 staining for paraffin-embedded gastric cancer tissues, and ITBCC recommended tumor budding evaluation method was used to count tumor budding in gastric cancer tissues. The factors affecting the prognosis of gastric cancer were analyzed.

RESULTS

There were 209 cases (35.54%) of P53 wild-type and 379 cases (64.46 %) of P53 mutant in 588 patients with stage Ⅰ-Ⅱ gastric cancer. P53 mutation rate were closely correlated with Lauren classification (χ² =8.152, p = 0.017), degree of differentiation (χ² =10.495, p = 0.004), number of lymph node metastasis (χ² =25.550, p < 0.001), and clinical stage (χ² =7.617, p = 0.016). Tumor budding were closely correlated with Lauren classification (χ² =194.533, p < 0.001), degree of tissue differentiation (χ² =22.719, p < 0.001), depth of tumor invasion (χ² =19.204, p = 0.004), number of lymph node metastasis (χ² =22.555, p = 0.001), clinical stage (χ² =10.769, p = 0.005), and vascular tumors bolt (χ² =12.478, p = 0.002). The higher the tumor budding grade was, the higher the P53 mutation rate was (χ² =12.933, p = 0.002). Lauren classification (p < 0.001), degree of tissue differentiation (p = 0.005), vascular tumors bolt (p < 0.001) and P53 mutation (p = 0.006) were independent influencing factors for 5-year survival of patients with stage Ⅰ-Ⅱ gastric cancer.

CONCLUSION

P53 mutation status is an independent prognostic factor for gastric cancer patients and a promising cancer treatment target. Tumor budding is a very reliable independent prognostic parameter with important clinical value and should be routinely reported as a biomarker.

A comprehensive study of p53 protein

The protein p53 has been extensively investigated since it was found 43 years ago and has become a "guardian of the genome" that regulates the division of cells by preventing the growth of cells and dividing them, that is, inhibits the development of tumors. Initial proof of protein existence by researchers in the mid-1970s was found by altering and regulating the SV40 big T antigen termed the A protein. Researchers demonstrated how viruses play a role in cancer by employing viruses' ability to create T-antigens complex with viral tumors, which was discovered in 1979 following a viral analysis and cancer analog research. Researchers later in the year 1989 explained that in Murine Friend, a virus-caused erythroleukemia, commonly found that p53 was inactivated to suggest that p53 could be a "tumor suppressor gene." The TP53 gene, encoding p53, is one of human cancer's most frequently altered genes. The protein-regulated biological functions of all p53s include cell cycles, apoptosis, senescence, metabolism of the DNA, angiogenesis, cell differentiation, and immunological response. We tried to unfold the history of the p53 protein, which was discovered long back in 1979, that is, 43 years of research on p53, and how p53's function has been developed through time in this article.

New insights in ferroptosis: Potential therapeutic targets for the treatment of ischemic stroke

Stroke is a common disease in clinical practice, which seriously endangers people's physical and mental health. The neurovascular unit (NVU) plays a key role in the occurrence and development of ischemic stroke. Different from other classical types of cell death such as apoptosis, necrosis, autophagy, and pyroptosis, ferroptosis is an iron-dependent lipid peroxidation-driven new form of cell death. Interestingly, the function of NVU and stroke development can be regulated by activating or inhibiting ferroptosis. This review systematically describes the NVU in ischemic stroke, provides a comprehensive overview of the regulatory mechanisms and key regulators of ferroptosis, and uncovers the role of ferroptosis in the NVU and the progression of ischemic stroke. We further discuss the latest progress in the intervention of ferroptosis as a therapeutic target for ischemic stroke and summarize the research progress and regulatory mechanism of ferroptosis inhibitors on stroke. In conclusion, ferroptosis, as a new form of cell death, plays a key role in ischemic stroke and is expected to become a new therapeutic target for this disease.

Improving cancer immunotherapy by rationally combining oncolytic virus with modulators targeting key signaling pathways

Oncolytic viruses (OVs) represent a new class of multi-modal immunotherapies for cancer, with OV-elicited antitumor immunity being key to their overall therapeutic efficacy. Currently, the clinical effectiveness of OV as monotherapy remains limited, and thus investigators have been exploring various combinations with other anti-cancer agents and demonstrated improved therapeutic efficacy. As cancer cells have evolved to alter key signaling pathways for enhanced cell proliferation, cancer progression and metastasis, these cellular and molecular changes offer promising targets for rational cancer therapy design. In this regard, key molecules in relevant signaling pathways for cancer cells or/and immune cells, such as EGFR-KRAS (e.g., KRAS^G12C), PI3K-AKT-mTOR, ERK-MEK, JAK-STAT, p53, PD-1-PD-L1, and epigenetic, or immune pathways (e.g., histone deacetylases, cGAS-STING) are currently under investigation and have the potential to synergize with OV to modulate the immune milieu of the tumor microenvironment (TME), thereby improving and sustaining antitumor immunity. As many small molecule modulators of these signaling pathways have been developed and have shown strong therapeutic potential, here we review key findings related to both OV-mediated immunotherapy and the utility of small molecule modulators of signaling pathways in immuno-oncology. Then, we focus on discussion of the rationales and potential strategies for combining OV with selected modulators targeting key cellular signaling pathways in cancer or/and immune cells to modulate the TME and enhance antitumor immunity and therapeutic efficacy. Finally, we provide perspectives and viewpoints on the application of novel experimental systems and technologies that can propel this exciting branch of medicine into a bright future.

Landscapes of synchronous multiple primary cancers detected by next-generation sequencing

An increase in the detection rate of multiple primary cancers has been accompanied with declining cancer death rates over the past few decades. However, synchronous multiple primary tumors have gradually increased, and the molecular mechanisms involved in the synchronous occurrence of multiple primary cancers of different origins are unclear. To investigate these mechanisms, we sequenced cancer tissues by FoundationOne CDx. Data were annotated with annovar, and we then performed pathway enrichment analysis. A total of 109 genes that were mutated in all samples were clustered into different diseases, biological processes, and molecular functions. GO and KEGG analyses indicated that the P53 and PKB signaling pathways may be relevant to the occurrence of synchronous multiple primary cancers. In summary, patients with a concordance of mutations in pathogenetic genes may have a higher risk of developing a second cancer. Our research may provide a basis for the development of individualized treatments for synchronous multiple primary cancers.

The complexity of p53-mediated metabolic regulation in tumor suppression

Although the classic activities of p53 including induction of cell-cycle arrest, senescence, and apoptosis are well accepted as critical barriers to cancer development, accumulating evidence suggests that loss of these classic activities is not sufficient to abrogate the tumor suppression activity of p53. Numerous studies suggest that metabolic regulation contributes to tumor suppression, but the mechanisms by which it does so are not completely understood. Cancer cells rewire cellular metabolism to meet the energetic and substrate demands of tumor development. It is well established that p53 suppresses glycolysis and promotes mitochondrial oxidative phosphorylation through a number of downstream targets against the Warburg effect. The role of p53-mediated metabolic regulation in tumor suppression is complexed by its function to promote both cell survival and cell death under different physiological settings. Indeed, p53 can regulate both pro-oxidant and antioxidant target genes for complete opposite effects. In this review, we will summarize the roles of p53 in the regulation of glucose, lipid, amino acid, nucleotide, iron metabolism, and ROS production. We will highlight the mechanisms underlying p53-mediated ferroptosis, AKT/mTOR signaling as well as autophagy and discuss the complexity of p53-metabolic regulation in tumor development.

Long noncoding RNA ST8SIA6-AS1 promotes cell proliferation and metastasis in triple-negative breast cancer by targeting miR-145-5p/CDCA3 to inactivate the p53/p21 signaling pathway

BACKGROUND

Triple-negative breast cancer (TNBC), the most aggressive subtype of breast cancer, always exhibits a poor prognosis due to high risk of early recurrence and distant metastasis. Long noncoding RNAs (lncRNAs) have been reported as crucial regulators in breast cancer. However, the functions and action mechanisms of lncRNA ST8SIA6-AS1 in TNBC are largely unknown.

METHODS

Quantitative real-time PCR and western blot assays were used to measure the expression levels of different genes and proteins. Cell proliferation ability was monitored by CCK-8, colony forming and flow cytometry assays. Wound healing and transwell assays were performed to evaluate cell migration and invasion. The regulatory mechanisms of ST8SIA6-AS1 in TNBC were confirmed by dual luciferase reporter and RIP assays. A mouse xenograft model was established to investigate the role of ST8SIA6-AS1 in TNBC tumor growth.

RESULTS

ST8SIA6-AS1 displayed a higher expression in TNBC cells. Silencing ST8SIA6-AS1 impaired cell proliferation, cell cycle progression, migration, and invasion in vitro, and slowed tumor growth in vivo. Mechanistically, ST8SIA6-AS1 could facilitate the expression of its target CDCA3 (cell division cycle associated protein 3) and inactivate the p53/p21 signaling by inhibiting miR-145-5p. Moreover, miR-145-5p exerted a tumor-suppressive activity by targeting CDCA3. The tumor-suppressive effects induced by ST8SIA6-AS1 knockdown were abated by the down-regulation of miR-145-5p or the up-regulation of CDCA3.

CONCLUSION

ST8SIA6-AS1 exerts an oncogenic role in TNBC by interacting with miR-145-5p to up-regulate CDCA3 expression and inactivate the p53/p21 signaling, highlighting ST8SIA6-AS1 as a promising molecular target to combat TNBC.

Recent findings on the role of wild-type and mutant p53 in cancer development and therapy

The p53 protein is a tumor suppressor encoded by the TP53 gene and consists of 393 amino acids with four main functional domains. This protein responds to various cellular stresses to regulate the expression of target genes, thereby causing DNA repair, cell cycle arrest, apoptosis, metabolic changes, and aging. Mutations in the TP53 gene and the functions of the wild-type p53 protein (wtp53) have been linked to various human cancers. Eight TP53 gene mutations are located in codons, constituting 28% of all p53 mutations. The p53 can be used as a biomarker for tumor progression and an excellent target for designing cancer treatment strategies. In wild-type p53-carrying cancers, abnormal signaling of the p53 pathway usually occurs due to other unusual settings, such as high MDM2 expression. These differences between cancer cell p53 and normal cells have made p53 one of the most important targets for cancer treatment. In this review, we have dealt with various issues, such as the relative contribution of wild-type p53 loss of function, including transactivation-dependent and transactivation-independent activities in oncogenic processes and their role in cancer development. We also discuss the role of p53 in the process of ferroptosis and its targeting in cancer treatment. Finally, we focus on p53-related drug delivery systems and investigate the challenges and solutions.

Necroptosis-Related Prognostic Signature and Nomogram Model for Predicting the Overall Survival of Patients with Lung Cancer

Background

Necroptosis is a type of programmed cell death mode and it serves an important role in the tumorigenesis and tumor metastasis. The purpose of this study is to develop a prognostic model based on necroptosis-related genes and nomogram for predicting the overall survival of patients with lung cancer.

Method

Differentially expressed necroptosis-related genes (NRDs) between lung cancer and normal samples were identified. Univariate and LASSO regression analyses were performed to establish a risk score (RS) model, followed by validation within TCGA and GSE37745. The correlation between RS model and tumor microenvironment, mutation status, or drug susceptibility was analyzed. By combining clinical factors, nomogram was developed to predict 1-, 3-, and 5-year survival probability of an individual. The biological function involved by different risk groups was conducted by GSEA.

Results

A RS model containing six NRDs (FLNC, PLK1, ID1, MYO1C, SERTAD1, and LEF1) was constructed, and patients were divieded into low-risk (LR) and high-risk (HR) groups. Patients in HR group were associated with shorter survival time than those in the LR group; this model had better prognostic performance. Nomogram based on necroptosis score, T stage, and stage had been confirmed to predict survival of patients. The number of resting NK cells and M0 macrophages was higher in HR group. In addition, higher tumor mutational burden and drug sensitivity were observed in the HR group. Patients in HR group were involved in p53 signaling pathway and cell cycle.

Conclusion

This study constructed a robust six-NRDs signature and established a prognostic nomogram for survival prediction of lung cancer.

Identification of a novel probiotic and its protective effects on NAFLD via modulating gut microbial community

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is becoming the most common progressive liver diseases. Therapeutic strategy based on gut-liver axis and probiotics is a promising approach for the treatment of NAFLD. However, rare probiotics have been applied in NAFLD treatment, and the involved molecular mechanism is not entirely clear.

RESULTS

We initially identified a novel functional probiotic, Lactobacillus kefiranofaciens ZW3, on the lipid deposition by a simple and rapid zebrafish model. Supplementation with ZW3 to the methionine and choline deficient (MCD) diet induced NAFLD rats could improve the liver impairments and reduce inflammation through TLR4-MyD88 and JNK signaling pathways. Moreover, ZW3 modulated gut microbiota by promoting relative abundance of Firmicutes and Lactobacillus, decreasing the abundance of Escherichia-Shigella and Bacteroides. Functional prediction of microbiome showed ZW3 presented potential enhancement on carbohydrate and lipid metabolism, cell process control and signal transduction processes, and reduced several human diseases.

CONCLUSION

This present study identified a novel probiotic and its protective effects on NAFLD, and interpreted the interactions of ZW3 with the immune system and gut microbiota involved in gut-liver axis. © 2022 Society of Chemical Industry.

An Updated View of the Roles of p53 in Embryonic Stem Cells

The TP53 gene is unarguably one of the most studied human genes. Its encoded protein, p53, is a tumor suppressor and is often called the "guardian of the genome" due to its pivotal role in maintaining genome stability. Historically, most studies of p53 have focused on its roles in somatic cells and tissues, but in the last two decades, its functions in embryonic stem cells (ESCs) and induced pluripotent stem cells have attracted increasing attention. Recent studies have identified p53 as a critical regulator of pluripotency, self-renewal, differentiation, proliferation, and genome stability in mouse and human embryonic stem cells. In this article, we systematically review the studies on the functions of p53 in ESCs, provide an updated overview, attempt to reconcile controversial results described in the literature, and discuss the relevance of these cellular functions of p53 to its roles in tumor suppression.

Chemosensitivity of gastric cancer: analysis of key pathogenic transcription factors

BACKGROUND

We aimed to screen the key pathogenic transcription factors of gastric cancer and analyzed the correlation between the expression of transcription factors and chemotherapy drugs in gastric cancer.

METHODS

Gastric cancer RNA sequencing data sets, single nucleotide polymorphism data sets, and corresponding clinical data sets were downloaded from The Cancer Genome Atlas, which is public data. The expression of transcription factors in gastric cancer and normal tissues was analyzed with R software. Pathway enrichment analysis of differentially expressed transcription factors was performed using the Kyoto Encyclopedia of Genes and Genomes database. Univariate Cox analysis was used to explore the correlation between the differential expression of transcription factors and prognosis. The interaction network among differentially expressed transcription factors was constructed using String database. Spearman test was used to explore the correlation between transcription factor mutation and gene expression. The Genomics of Drug Sensitivity in Cancer database was used to examine the relationship between the expression of transcription factors and chemotherapeutic drug sensitivity.

RESULTS

A total of 17 differentially expressed transcription factors were screened. The results indicated that CENPA, E2F1, EMX1, HOXA9, FOXM1, and MYBL2 were prognostic risk factors for gastric cancer patients (P<0.05), while RXRG and SOX4 were prognostic protective factors for gastric cancer patients (P<0.05). FDXM1 interacted with E2F7, MYBL2, E2F1, NCAPG, and SOX9. FOXM1 gene mutation was positively correlated with the expression level (P<0.05). Based on the median value of FOXM1, the patients were divided into high expression group and low expression group of FOXM1. There was no significant difference in IC50 of 5-fluorouracil between the FOXM1 high expression group and the FOXM1 low expression group (P>0.05). The IC50 of paclitaxel in the FOXM1 high expression group was higher than that in the FOXM1 low expression group (P<0.001). The expression of IC50 of cisplatin in the FOXM1 high expression group was higher than that in the FOXM1 low expression group (P<0.05).

CONCLUSIONS

FOXM1 was a highly expressed transcription factor in gastric cancer. High FOXM1 expression was associated with the resistance of gastric cancer patients to paclitaxel and cisplatin. Therefore, FOXM1 is a potential therapeutic target for gastric cancer.

A Bibliometric Analysis of Triptolide and the Recent Advances in Treating Non-Small Cell Lung Cancer

In recent decades, natural products derived from plants and their derivatives have attracted great interest in the field of disease treatment. Triptolide is a tricyclic diterpene extracted from Tripterygium wilfordii, a traditional Chinese medicine, which has shown excellent therapeutic potential in the fields of immune inflammation and cancer treatment. In this study, 1,106 Web-of-Science-indexed manuscripts and 1,160 Chinese-National-Knowledge-Infrastructure-indexed manuscripts regarding triptolide published between 2011 and 2021 were analyzed, mapping the co-occurrence networks of keywords and clusters using CiteSpace software. The research frontier and development trend were determined by keyword frequency and cluster analysis, which can be used to predict the future research development of triptolide. Non-small cell lung cancer (NSCLC) is most common in lung cancer patients, accounting for about 80% of all lung cancer patients. New evidence suggests that triptolide effectively inhibits the development and metastasis of NSCLC by the induction of apoptosis, reversion of EMT, and regulation of gene expression. Specifically, it acts on NF-κB, MAPKs, P53, Wnt/β-catenin, and microRNAs (miRNAs), signaling pathways and molecular mechanisms. Consequently, this article reviews the research progress of the anti-NSCLC effect of triptolide. In addition, attenuated studies on triptolide and the potential of tumor immunotherapy are also discussed.

DNA hypermethylation modification promotes the development of hepatocellular carcinoma by depressing the tumor suppressor gene ZNF334

DNA methylation plays a pivotal role in the development and progression of tumors. However, studies focused on the dynamic changes of DNA methylation in the development of hepatocellular carcinoma (HCC) are rare. To systematically illustrate the dynamic DNA methylation alternation from premalignant to early-stage liver cancer with the same genetic background, this study enrolled 5 HBV-related patients preceded with liver cirrhosis, pathologically identified as early-stage HCC with dysplastic nodules. Liver fibrosis tissues, dysplastic nodules and early HCC tissues from these patients were used to measure DNA methylation. Here, we report significant differences in the DNA methylation spectrum among the three types of tissues. In the early stage of HCC, DNA hypermethylation of tumor suppressor genes is predominant. Additionally, DNA hypermethylation in the early stage of HCC changes the binding ability of transcription factor TP53 to the promoter of tumor suppressor gene ZNF334, and inhibits the expression of ZNF334 at the transcription level. Furthermore, through a series of in vivo and in vitro experiments, we have clarified the exacerbation effect of tumor suppressor gene ZNF334 deletion in the occurrence of HCC. Combined with clinical data, we found that the overall survival and relapse-free survival of patients with high ZNF334 expression are significantly longer. Thus, we partly elucidated a sequential alternation of DNA methylation modification during the occurrence of HCC, and clarified the biological function and regulatory mechanism of the tumor suppressor gene ZNF334, which is regulated by related DNA methylation sites. Our study provides a new target and clinical evidence for the early diagnosis and sheds light on the precise treatment of liver cancer.

p53 in ferroptosis regulation: the new weapon for the old guardian

Although the conventional activities of p53 such as cell cycle arrest, senescence, and apoptosis are well accepted as the major checkpoints in stress responses, accumulating evidence implicates the importance of other tumor suppression mechanisms. Among these unconventional activities, an iron-dependent form of non-apoptotic cell death, termed ferroptosis, attracts great interest. Unlike apoptotic cell death, activation of p53 alone is not sufficient to induce ferroptosis directly; instead, through its metabolic targets, p53 is able to modulate the ferroptosis response in the presence of ferroptosis inducers such as GPX4 inhibitors or high levels of ROS. Here, we review the role of ferroptosis in p53-mediated tumor suppression, with a focus on what cellular factors are critical for p53-dependent ferroptosis during tumor suppression and how p53 modulates both the canonical (GPX4-dependent) and the non-canonical (GPX4-independent) ferroptosis pathways. We also discuss the possibility of targeting p53-mediated ferroptotic responses for the treatment of human cancers and potentially, other diseases.

Identifying the shared genes and KEGG pathways of Resolvin D1-targeted network and osteoarthritis using bioinformatics

Osteoarthritis (OA) is a common chronic degenerative disease characterized by the loss of articular cartilage, which causes loss of joint function and reduce quality of life. Resolvin D1 (RvD1) has shown interesting anti-inflammatory effects; however, the mechanism of action of RvD1 in OA remains unclear. The aim of this study was to investigate the potential mechanism of RvD1 in OA by bioinformatics and partial in vitro mechanisms. Here, 106 shared differentially expressed genes (DEGs) were identified based on the GSE82107, GSE55235, GSE55457 dataset; 700 DEGs were identified based on GSE169077. Enrichment analyses of these genes were then successively conducted. RvD1-targeted genes and KEGG pathways are identified by STITCH. 27 shared KEGG pathways were identified among RvD1-targeted pathways and OA. Furthermore, cell apoptosis assay, western blotting, real-time fluorescent quantitative PCR (qRT-PCR), enzyme linked immunosorbent assay (ELISA) were used to confirm the expression levels of the key genes of shared Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways between RvD1-targeted and OA in IL-1β treated rat knee chondrocytes. The results showed that RvD1-targeted pathways and the expression of nuclear p65, p53, and p-JNK were inhibited in the RvD1 group compared with the IL-1β group. Thus, the findings indicate that RvD1 may inhibit the development of OA through NF/kB, p53, MAPK/JNK, PI3K-AKT signaling pathways, and act as a treatment for OA.

Advanced Strategies for Therapeutic Targeting of Wild-Type and Mutant p53 in Cancer

TP53 is a tumor suppressor gene that encodes a sequence-specific DNA-binding transcription factor activated by stressful stimuli; it upregulates target genes involved in growth suppression, cell death, DNA repair, metabolism, among others. TP53 is the most frequently mutated gene in tumors, with mutations not only leading to loss-of-function (LOF), but also gain-of-function (GOF) that promotes tumor progression, and metastasis. The tumor-specific status of mutant p53 protein has suggested it is a promising target for cancer therapy. We summarize the current progress of targeting wild-type and mutant p53 for cancer therapy through biotherapeutic and biopharmaceutical methods for (1) boosting p53 activity in cancer, (2) p53-dependent and p53-independent strategies for targeting p53 pathway functional restoration in p53-mutated cancer, (3) targeting p53 in immunotherapy, and (4) combination therapies targeting p53, p53 checkpoints, or mutant p53 for cancer therapy.

Cross-Talk between p53 and Wnt Signaling in Cancer

Targeting cancer hallmarks is a cardinal strategy to improve antineoplastic treatment. However, cross-talk between signaling pathways and key oncogenic processes frequently convey resistance to targeted therapies. The p53 and Wnt pathway play vital roles for the biology of many tumors, as they are critically involved in cancer onset and progression. Over recent decades, a high level of interaction between the two pathways has been revealed. Here, we provide a comprehensive overview of molecular interactions between the p53 and Wnt pathway discovered in cancer, including complex feedback loops and reciprocal transactivation. The mutational landscape of genes associated with p53 and Wnt signaling is described, including mutual exclusive and co-occurring genetic alterations. Finally, we summarize the functional consequences of this cross-talk for cancer phenotypes, such as invasiveness, metastasis or drug resistance, and discuss potential strategies to pharmacologically target the p53-Wnt interaction.

Curcumin analog HO-3867 triggers apoptotic pathways through activating JNK1/2 signalling in human oral squamous cell carcinoma cells

Human oral squamous cell carcinoma (OSCC) is the common head and neck malignancy in the world. While surgery, radiotherapy and chemotherapy are emerging as the standard treatment for OSCC patients, the outcome is limited to the recurrence and side effects. Therefore, patients with OSCC require alternative strategies for treatment. In this study, we aimed to explore the therapeutic effect and the mode of action of the novel curcumin analog, HO-3867, against human OSCC cells. We analysed the cytotoxicity of HO-3867 using MTT assay. In vitro mechanic studies were performed to determine whether MAPK pathway is involved in HO-3867 induced cell apoptosis. As the results, we found HO-3867 suppressed OSCC cells growth effectively. The flow cytometry data indicate that HO-3867 induce the sub-G1 phase. Moreover, we found that HO-3867 induced cell apoptosis by triggering formation of activated caspase 3, caspase 8, caspase 9 and PARP. After dissecting MAPK pathway, we found HO-3867 induced cell apoptosis via the c-Jun N-terminal kinase (JNK)1/2 pathway. Our results suggest that HO-3867 is an effective anticancer agent as its induction of cell apoptosis through JNK1/2 pathway in human oral cancer cells.

Biomarker Value of miR-221 and miR-222 as Potential Substrates in the Differential Diagnosis of Papillary Thyroid Cancer Based on Data Synthesis and Bioinformatics Approach

Background

MicroRNA (miRNA) has been reported to play a critical regulatory role in papillary thyroid carcinomas (PTC). However, the role of miR-221/222 in PTC remains unclear. Here, we performed this study to explore the diagnostic potentials and mechanisms of miR-221/222 in PTC.

Methods

First, we systematically analyzed the diagnostic value of miR-221/222 in the diagnosis PTC by pooling the published studies. Afterwards, we performed comprehensive bioinformatics analysis including gene ontology analysis, pathway enrichment analysis and protein-protein interaction analysis to explore the potential mechanisms of miR-221/222 involved in PTC.

Results

The overall sensitivity and specificity of miR-221/222 for PTC were 0.75 (95% CI: 0.70-0.80) and 0.80 (95% CI: 0.76-0.84) respectively with the AUC of 0.85 (95% CI: 0.81-0.88). The diagnostic performance varied among different subgroups including geographical locations, sample sources and sample sizes. Meanwhile, we found that a combination of miR-221/222 and other miRNAs when used in a diagnostic panel could improve the diagnostic accuracy than individual miR-221/222. Moreover, through the bioinformatics analysis, we confirmed that miR-221/222 targets were highly related to the molecular pathogenesis of PTC. The results revealed that miR-221/222 may exert important functions in PTC through thyroid hormone signaling pathway and some other key pathways by regulating some key genes.

Conclusion

These findings indicated that miR-221/222 have the potential to serve as auxiliary tools for diagnosing PTC. Further prospective clinical trials should be performed to assess the accuracy of these findings in a larger cohort and determine the clinical uses.

CircRNA-miRNA networks in regulating bone disease

Circular RNA (circRNA) is a class of endogenous noncoding RNA (ncRNA), presenting as a special covalent closed loop without a 5' cap or 3' tail, maintaining resistance to RNA exonuclease and keeping high stability. Although lowly expressed in most situations, circRNA makes an active difference in regulating physiological or pathological processes by modulating gene expression by regulation of transcription, protein, and miRNA functions through various mechanisms in particular tissues. Recent studies have demonstrated the roles of the miRNA-circRNA network in the development of several bone diseases such as osteoporosis, a multiple-mechanism disease resulting from defective bone quality and low bone mass, osteoarthritis, whose main pathomechanism is inflammation and articular cartilage degradation, as well as osteosarcoma, known as one of the most common bone cancers. However, the specific mechanism of how circRNA along with miRNA influences those diseases is not well documented, showing potential for the development of new therapies for those bone diseases.

A potential inhibitor of MDM2 by restoring the native conformation of the p53 α-helical peptide on gold nanoparticles

Many efforts have been made to develop inhibitors of MDM2 as potential drugs for cancer therapy. In this work, we use our previous developed conformational engineering technique to stabilize the binding conformation of the p53 transcription activation domain (TAD) peptide on gold NPs (AuNPs), and create an AuNP-based anti-MDM2 artificial antibody, denoted as Goldbody, that specifically binds MDM2. Though the free TAD peptide is unstructured, circular dichroism spectra confirm that its α-helical conformation in the original p53 protein is restored on the anti-MDM2 Goldbody, and surface plasmon resonance (SPR) experiments confirm that there is strong specific interaction between the anti-MDM2 Goldbody and MDM2, demonstrating the anti-MDM2 Goldbody as a potential inhibitor of MDM2. This work demonstrates that the conformational engineering technique is not limited to the antigen-antibody systems, but can also be applied more widely in other protein-protein interfaces to create more and more artificial proteins for various biomedical applications.

PVT1 is a prognostic marker associated with immune invasion of bladder urothelial carcinoma

Plasmacytoma variant translocation 1 (PVT1) is involved in multiple signaling pathways and plays an important regulatory role in a variety of malignant tumors. However, its role in the prognosis and immune invasion of bladder urothelial carcinoma (BLCA) remains unclear. This study investigated the expression of PVT1 in tumor tissue and its relationship with immune invasion, and determined its prognostic role in patients with BLCA. Patients were identified from the cancer genome atlas (TCGA). The enrichment pathway and function of PVT1 were explained by gene ontology (GO) term analysis, gene set enrichment analysis (GSEA) and single-sample gene set enrichment analysis (ssGSEA), and the degree of immune cell infiltration was quantified. Kaplan-Meier analysis and Cox regression were used to analyze the correlation between PVT1 and survival rate. PVT1-high BLCA patients had a lower 10-year disease-specific survival (DSS P < 0.05) and overall survival (OS P < 0.05). Multivariate Cox regression analysis showed that PVT1 (high vs. low) (P = 0.004) was an independent prognostic factor. A nomogram was used to predict the effect of PVT1 on the prognosis. PVT1 plays an important role in the progression and prognosis of BLCA and can be used as a medium biomarker to predict survival after cystectomy.

Immunological perspective on the malignant progression of renal clear cell carcinoma

Background

Clear cell renal cell carcinoma (ccRCC) is the most common malignancy affecting the kidneys, accounting for approximately 75% of all kidney tumors. Recently, the impact of immune response, immunotherapy, and immune-related genes (IRGs) on tumor development has received much attention. This study sought to establish a reliable immunological signature and further explore whether this signature has prognostic significance in ccRCC patients.

Methods

Differentially expressed IRGs in 611 patients with diagnosis of ccRCC from The Cancer Genome Atlas (TCGA) were analyzed along with the corresponding survival time and disease clinical data. Survival analysis, selection operator Cox analysis, and minimum absolute shrinkage were applied to establish an IRG prognostic signature (IRGPS). The expression levels of relevant genes were detected by real-time quantitative PCR. A Nomogram was used to explore the possible impact of the IRGPS on the immune system, prognosis, and metastasis, and the associated mechanisms were explored through functional enrichment analysis.

Results

An IRGPS was established based on eight prognostic IRGs and was found to be closely associated with immune levels, metastasis, and prognosis. The IRGPS was determined to be a valid predictor of the efficacy of immune checkpoint inhibitors (ICIs). Three Nomograms based on the IRGPS and other clinical features were developed and could effectively predict prognosis, distant metastasis, and lymph node metastasis in patients with ccRCC.

Conclusions

The IRGPS constructed in this study serves as a tool for assessing immune status, developing individualized treatment regimens, and predicting prognosis in patients with ccRCC.

Expert consensus on the clinical application of recombinant adenovirus human p53 for head and neck cancers

The first gene therapy product, recombinant adenovirus human p53 (rAd-p53 ), has been approved by CFDA since 2013. During these years, most of the clinical trials and the relevant basic research were carried out by Chinese oncologists. Gendicine was proved to be a safe and promising gene therapy drug for patients who suffered from head and neck squamous cell carcinoma (HNSCC). The basic therapeutic theories of gene therapy were totally different from the traditional ones, such as surgeries or radio- and chemotherapy, and the evaluation of treatment outcomes should also be changed simultaneously. However, there still existed a lot of misunderstandings about gene therapy, which resulted in improper administration, insufficient dosage calculation, and treatment cycles, and the treatment outcomes were unsatisfactory, especially for inexperienced oncologists or hospitals. Therefore, we will provide some practical guidance here on the gene therapy of rAd-p53 based on our previous research and experience, which focused on the basic theories and clinical issues, to answer the questions arising during the clinical of gene therapy and to accelerate the development of gene therapy for the benefit of patients bearing malignant tumors.

Clinical and Immunological Effects of p53-Targeting Vaccines

Immunotherapy, including immune checkpoint blockade and chimeric antigen receptor T cells, is one of the most promising approaches to treat cancer. Vaccines have been effective in preventing cancers like liver cancer and cervical cancer with a viral etiology. Instead of preventing disease, therapeutic cancer vaccines mobilize the immune system to attack existing cancer. p53 is dysregulated in the majority of human cancers and is a highly promising target for cancer vaccines. Over twenty clinical trials have targeted p53 in malignant diseases using vaccines. In this work, we review the progress of vaccinations with p53 or its peptides as the antigens and summarize the clinical and immunological effects of p53-targeting vaccines from clinical trials. The delivery platforms include p53 peptides, viral vectors, and dendritic cells pulsed with short peptides or transduced by p53-encoding viruses. These studies shed light on the feasibility, safety, and clinical benefit of p53 vaccination in select groups of patients, implicating that p53-targeting vaccines warrant further investigations in experimental animals and human studies.

Beyond the Double-Strand Breaks: The Role of DNA Repair Proteins in Cancer Stem-Cell Regulation

Simple Summary

Cancer stem cells (CSCs) are a tumor cell population maintaining tumor growth and promoting tumor relapse if not wholly eradicated during treatment. CSCs are often equipped with molecular mechanisms making them resistant to conventional anti-cancer therapies whose curative potential depends on DNA damage-induced cell death. An elevated expression of some key DNA repair proteins is one of such defense mechanisms. However, new research reveals that the role of critical DNA repair proteins is extending far beyond the DNA repair mechanisms. This review discusses the diverse biological functions of DNA repair proteins in CSC maintenance and the adaptation to replication and oxidative stress, anti-cancer immune response, epigenetic reprogramming, and intracellular signaling mechanisms. It also provides an overview of their potential therapeutic targeting.

Abstract

Cancer stem cells (CSCs) are pluripotent and highly tumorigenic cells that can re-populate a tumor and cause relapses even after initially successful therapy. As with tissue stem cells, CSCs possess enhanced DNA repair mechanisms. An active DNA damage response alleviates the increased oxidative and replicative stress and leads to therapy resistance. On the other hand, mutations in DNA repair genes cause genomic instability, therefore driving tumor evolution and developing highly aggressive CSC phenotypes. However, the role of DNA repair proteins in CSCs extends beyond the level of DNA damage. In recent years, more and more studies have reported the unexpected role of DNA repair proteins in the regulation of transcription, CSC signaling pathways, intracellular levels of reactive oxygen species (ROS), and epithelial–mesenchymal transition (EMT). Moreover, DNA damage signaling plays an essential role in the immune response towards tumor cells. Due to its high importance for the CSC phenotype and treatment resistance, the DNA damage response is a promising target for individualized therapies. Furthermore, understanding the dependence of CSC on DNA repair pathways can be therapeutically exploited to induce synthetic lethality and sensitize CSCs to anti-cancer therapies. This review discusses the different roles of DNA repair proteins in CSC maintenance and their potential as therapeutic targets.

A Novel Integrated Metabolism-Immunity Gene Expression Model Predicts the Prognosis of Lung Adenocarcinoma Patients

Background: Although multiple metabolic pathways are involved in the initiation, progression, and therapy of lung adenocarcinoma (LUAD), the tumor microenvironment (TME) for immune cell infiltration that is regulated by metabolic enzymes has not yet been characterized.

Methods: 517 LUAD samples and 59 non-tumor samples were obtained from The Cancer Genome Atlas (TCGA) database as the training cohort. Kaplan-Meier analysis and Univariate Cox analysis were applied to screen the candidate metabolic enzymes for their role in relation to survival rate in LUAD patients. A prognostic metabolic enzyme signature, termed the metabolic gene risk score (MGRS), was established based on multivariate Cox proportional hazards regression analysis and was verified in an independent test cohort, GSE31210. In addition, we analyzed the immune cell infiltration characteristics in patients grouped by their Risk Score. Furthermore, the prognostic value of these four enzymes was verified in another independent cohort by immunohistochemistry and an optimized model of the metabolic-immune protein risk score (MIPRS) was constructed.

Results: The MGRS model comprising 4 genes (TYMS, NME4, LDHA, and SMOX) was developed to classify patients into high-risk and low-risk groups. Patients with a high-risk score had a poor prognosis and exhibited activated carbon and nucleotide metabolism, both of which were associated with changes to TME immune cell infiltration characteristics. In addition, the optimized MIPRS model showed more accurate predictive power in prognosis of LUAD.

Conclusion: Our study revealed an integrated metabolic enzyme signature as a reliable prognostic tool to accurately predict the prognosis of LUAD.

A microRNA-clinical prognosis model to predict the overall survival for kidney renal clear cell carcinoma

Numerous studies have shown that microRNA (miRNA) serves as key regulatory factors in the origin and development of cancers. However, the biological mechanisms of miRNAs in kidney renal clear cell carcinoma (KIRC) are still unknown. It is necessary to construct an effective miRNA‐clinical model to predict the prognosis of KIRC. In this study, 94 differentially expressed miRNAs were found between para‐tumor and tumor tissues based on the Cancer Genome Atlas (TCGA) database. Seven miRNAs (hsa‐miR‐21‐5p, hsa‐miR‐3613‐5p, hsa‐miR‐144‐5p, hsa‐miR‐376a‐5p, hsa‐miR‐5588‐3p, hsa‐miR‐1269a, and hsa‐miR‐137‐3p) were selected as prognostic indicators. According to their cox coefficient, a risk score formula was constructed. Patients with risk scores were divided into high‐ and low‐risk groups based on the median score. Kaplan–Meier curves analysis showed that the low‐risk group had a better survival probability compared to the high‐risk group. The area under the ROC curve (AUC) value of the miRNA model was 0.744. In comparison with clinical features, the miRNA model risk score was considered as an independent prognosis factor in multivariate Cox regression analysis. In addition, we built a nomogram including age, metastasis, and miRNA prognostic model based on the results of multivariate Cox regression analysis. The decision curve analysis (DCA) revealed the clinical net benefit of the prognostic model. Gene set enrichment analysis (GSEA) results suggested that several important pathways may be the potential pathways for KIRC. The results of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis for the target genes of 7 miRNAs revealed that miRNAs may participate in KIRC progression via many specific pathways. Additionally, the levels of seven prognostic miRNAs showed a significant difference between KIRC tissues and adjacent non‐tumorous tissues. In conclusion, the miRNA‐clinical model provides an effective and accurate way to predict the prognosis of KIRC.

Ubiquitin-Like Protein UBD Promotes Cell Proliferation in Colorectal Cancer by Facilitating p53 Degradation

Purpose

Ubiquitin D (UBD) is a member of the ubiquitin-like modifier (UBL) family and is highly expressed in a variety of cancers including colorectal cancer (CRC). However, the mechanisms of its regulatory roles in CRC are largely elusive. In this study, we revealed the effect of UBD on the proliferation of CRC.

Methods

The expression of UBD in clinical tissue samples of CRC and seven CRC cell lines was detected using qRT-PCR, immunohistochemistry (IHC) and Western blotting. CCK-8, colony formation, EdU and flow cytometry assays were used to detect the functional changes of CRC cells transfected with UBD stable expression plasmids in vitro. A xenograft model was constructed to assess the effect of UBD on the growth of CRC cells in vivo. The connection between UBD and p53 was analyzed using Western blotting, immunoprecipitation, proteasome inhibition assay and Cycloheximide (CHX) chase assay.

Results

UBD was overexpressed in CRC tumor tissues compared with nontumor tissues, and its overexpression was positively associated with the tumor size and TNM stage of CRC patients. Functionally, UBD significantly accelerated CRC cell viability and proliferation in vitro and promoted tumorigenesis in vivo. Mechanistically, UBD interacted with p53 in CRC cells, downregulated the expression of p53 by regulating its degradation, shortened the p53 half-life, thereby further affecting the decrease in p21 and the increase in Cyclin D1, Cyclin E, CDK2, CDK4 and CDK6. Moreover, in vivo experiments showed that UBD-induced tumor growth in nude mice was dependent on a decrease in p53.

Conclusions

Our study proved that UBD mediates the degradation of p53, thereby facilitating the growth of CRC cells and ultimately promoting the progression of CRC. Therefore, UBD may be a potential therapeutic target and a promising prognostic biomarker for CRC.

CBFB cooperates with p53 to maintain TAp73 expression and suppress breast cancer

The CBFB gene is frequently mutated in several types of solid tumors. Emerging evidence suggests that CBFB is a tumor suppressor in breast cancer. However, our understanding of the tumor suppressive function of CBFB remains incomplete. Here, we analyze genetic interactions between mutations of CBFB and other highly mutated genes in human breast cancer datasets and find that CBFB and TP53 mutations are mutually exclusive, suggesting a functional association between CBFB and p53. Integrated genomic studies reveal that TAp73 is a common transcriptional target of CBFB and p53. CBFB cooperates with p53 to maintain TAp73 expression, as either CBFB or p53 loss leads to TAp73 depletion. TAp73 re-expression abrogates the tumorigenic effect of CBFB deletion. Although TAp73 loss alone is insufficient for tumorigenesis, it enhances the tumorigenic effect of NOTCH3 overexpression, a downstream event of CBFB loss. Immunohistochemistry shows that p73 loss is coupled with higher proliferation in xenografts. Moreover, TAp73 loss-of-expression is a frequent event in human breast cancer tumors and cell lines. Together, our results significantly advance our understanding of the tumor suppressive functions of CBFB and reveal a mechanism underlying the communication between the two tumor suppressors CBFB and p53.

CSNK2B contributes to colorectal cancer cell proliferation by activating the mTOR signaling

The function of Casein kinase 2 beta (CSNK2B) in human malignancies has drawn increasing attention in recent years. However, its role in colorectal cancer (CRC) remains unclear. In the present study, we aimed to explore the expression and biological functions of CSNK2B in CRC. Public gene expression microarray data from online database and immunohistochemistry analysis demonstrated that CSNK2B was highly expressed in CRC tissues than in normal tissues. In vitro and in vivo cellular functional experiments showed that increased CSNK2B expression promoted CRC cell viability and tumorigenesis of CRC. Further western blots and rescue experiments confirmed that CSNK2B promoted CRC cell proliferation mainly by activating the mTOR signaling pathway. These findings identified CSNK2B as a novel oncogene contributing to the development of CRC.

Targeting SIRT1 to inhibit the proliferation of multiple myeloma cells

Multiple myeloma (MM) is the second most common hematopoietic malignancy and remains an incurable disease. Thus, novel drugs and therapeutic methods are required for patients with MM. The present study aimed to investigate the effect of sirtuin 1 (SIRT1) inhibitor cambinol on the proliferation and apoptosis of myeloma cell lines, RPMI8226 and U266. Moreover, the present study evaluated the underlying molecular mechanisms of proliferation inhibition and apoptosis induced by cambinol. A Cell Counting Kit-8 assay was used to measure the viability of RPMI8226 and U266 cells treated with cambinol. Apoptosis and the cell cycle were analyzed via flow cytometry. The expression levels of caspase-3, poly(ADP-ribose) polymerase 1 (PARP), p53, acetylated p53 (Ac-p53), Bcl-2, cyclin D1 and p21 were detected in cells treated with cambinol using western blot analysis. The results demonstrated that cambinol inhibited the proliferation of RPMI8226 and U266 cells in a time- and dose-dependent manner. Increased apoptosis and G₁ cell cycle arrest, together with enhanced procaspase-3 degradation and PARP cleavage were identified in cambinol-treated cells compared with controls. Western blotting results also revealed the upregulation of p53 acetylation and p21, as well as the downregulation of Bcl-2 and cyclin D1 in cells treated with cambinol. In conclusion, the present results suggest that cambinol inhibits the proliferation and induces apoptosis in RPMI8226 and U266 cells by regulating acetylation of p53 via the targeting of SIRT1.

STAT3 and p53: Dual Target for Cancer Therapy

The tumor suppressor p53 is considered the "guardian of the genome" that can protect cells against cancer by inducing cell cycle arrest followed by cell death. However, STAT3 is constitutively activated in several human cancers and plays crucial roles in promoting cancer cell proliferation and survival. Hence, STAT3 and p53 have opposing roles in cellular pathway regulation, as activation of STAT3 upregulates the survival pathway, whereas p53 triggers the apoptotic pathway. Constitutive activation of STAT3 and gain or loss of p53 function due to mutations are the most frequent events in numerous cancer types. Several studies have reported the association of STAT3 and/or p53 mutations with drug resistance in cancer treatment. This review discusses the relationship between STAT3 and p53 status in cancer, the molecular mechanism underlying the negative regulation of p53 by STAT3, and vice versa. Moreover, it underlines prospective therapies targeting both STAT3 and p53 to enhance chemotherapeutic outcomes.