E2F Transcription Factor 1 Activates FKBP Prolyl Isomerase 4 to Promote Angiogenesis in Cervical Squamous Cell Carcinoma Via the PI3K/AKT Signaling Pathway

The RB protein: more than a sentry of cell cycle entry

Genomic instability is a hallmark of cancer. It fuels cancer progression and therapy resistance. As 'the guardian of the genome', the tumor suppressor protein p53 protects against genomic damage. Canonically, the retinoblastoma protein (RB) is 'the sentry of cell cycle entry', as it dictates whether a cell enters the cell cycle to divide. However, the RB pathway also controls myriad non-canonical cellular processes, including metabolism, stemness, angiogenesis, apoptosis, and immune surveillance. We discuss how frequent RB pathway inactivation and underlying mechanisms in cancers affect these processes. We focus on RB's - rather than p53's - 'guardian of the genome' functions in DNA replication, DNA repair, centrosome duplication, chromosome segregation, and chromatin organization. Finally, we review therapeutic strategies, challenges, and opportunities for targeting RB pathway alterations in cancer.

E2F1-Dependent CDCA5 overexpression drives cervical cancer progression and correlates with poor prognosis

Cervical cancer (CC) remains a leading cause of cancer-related mortality in women worldwide, highlighting the urgent need for novel therapeutic strategies. This study investigates the molecular mechanisms and clinical significance of Cell Division Cycle Associated 5 (CDCA5) in cervical cancer progression. We performed comprehensive analyses of CDCA5 expression in cervical cancer and normal tissues, correlating expression levels with clinicopathological features and patient outcomes. Functional studies using CC cell lines (SiHa, HeLa, and CaSki) examined the effects of CDCA5 manipulation on tumor cell behavior. We identified E2F1 as a key transcriptional regulator of CDCA5 and validated our findings using in vivo xenograft models. CDCA5 was significantly upregulated in CC tissues and correlated with advanced disease stages and poor survival outcomes. Mechanistically, CDCA5 depletion in SiHa and HeLa cells suppressed proliferation, migration, and invasion, while its overexpression in CaSki cells enhanced these malignant properties. We identified E2F1 as a transcriptional activator of CDCA5. Importantly, CDCA5 knockdown significantly inhibited tumor growth in nude mouse models. Our findings establish CDCA5 as a critical E2F1-regulated oncogenic factor in cervical cancer progression. The strong correlation between CDCA5 expression and poor clinical outcomes suggests its potential as both a prognostic biomarker and therapeutic target in cervical cancer treatment.

E2F1 and E2F7 regulate gastric cancer cell proliferation, respectively, through transcriptional activation and transcriptional repression of MYBL2

Gastric cancer (GC) is the most common malignant tumor of the digestive tract. However, the molecular pathogenesis is not well understood. Through bioinformatic analysis and analyzing clinical tissue samples, we found that E2F1 and E2F7 as well as their potential downstream target MYBL2 were all upregulated in GC tissues and that their expressions correlated with patient prognosis. While knockdown of E2F1 or MYBL2 inhibited cell proliferation and promoted apoptosis, knockdown of E2F7 promoted cell proliferation but had no effects on apoptosis. Chromatin immunoprecipitation and dual luciferase reporter assays demonstrated that MYBL2 was transcriptionally activated and repressed by E2F1 and E2F7, respectively. Importantly, in vitro and ex vivo experiments demonstrated that the effects of E2F1 and E2F7 on GC cell proliferation were significantly attenuated by reversely modulating MYBL2 expression, indicating that MYBL2 is a direct and functionally relevant target of E2F1 and E2F7 in GC cells. Furthermore, the effects of E2F1 and E2F7 on GC cell proliferation through transcriptional regulation of MYBL2 can be mediated by the PI3K/AKT signaling pathway. Interestingly, we found differential nucleocytoplasmic distribution of E2F7 in GC cells with functional relevance. Taken together, our data suggest that targeted therapies of GC may be achieved from three different angles, E2F1, E2F7, and MYBL2 themselves, E2F1/E2F7 expression balance, and E2F7 nuclear localization.

Research advances in signaling pathways related to the malignant progression of HSIL to invasive cervical cancer: A review

The progression of high-grade squamous intraepithelial lesion (HSIL) to invasive cervical cancer (ICC) is a complex process involving persistent human papillomavirus (HPV) infection and changes in signal transduction regulation, energy and material metabolism, cell proliferation, autoimmune, and other biological process in vaginal microenvironment and immune microenviroment. Signaling pathways are a series of interacting molecules in cells that regulate various physiological functions of cells, such as growth, differentiation, metabolism, and death. In the progression of HSIL to ICC, abnormal activation or inhibition in signaling pathways plays an essensial role. This review presented some signaling pathways related to the malignant progression of HSIL to ICC, including p53, Rb, PI3K/AKT/mTOR, Wnt/β-catenin, Notch, NF-κB, MAPK, TGF-β, JAK-STAT, Hippo, and Hedgehog. The molecular mechanisms involved in the biological process of pathway regulation were also analyzed, in order to illustrate the molecular pathway of HSIL progression to ICC and provide references for the development of more effective prevention and treatment methods.

LncRNA LINC01703 promotes the proliferation, migration, and invasion of colorectal cancer by activating PI3K/AKT pathway

The role of LINC01703 in cancers, especially in colorectal cancer (CRC), is still largely unclear. Bioinformatics prediction, real-time quantitative polymerase chain reaction (RT-qPCR), 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide (MTT) assay, colony formation assay, Transwell assays, in vivo animal experiments, IF, luciferase reporter assay, and Western blot were carried out for the exploration of the potential involvement and underlying molecular mechanisms of LINC01703 in CRC cells. The results showed that LINC01703 appeared upregulated in CRC and was linked to poor prognosis. LINC01703 acted as an oncogene in both in vitro and in vivo CRC cell environments. LINC01703 activated the PI3K/AKT signaling pathway by mediating the miR-205-5p/E2F1 axis in CRC. In summary, LINC01703 possesses an oncogenic function and can be a possible biomarker or target to treat CRC.

A cellular senescence-related genes model allows for prognosis and treatment stratification of cervical cancer: a bioinformatics analysis and external verification

BACKGROUND

Cervical cancer (CC) is highly lethal and aggressive with an increasing trend of mortality for females. Molecular characterization-based methods hold great promise for improving the diagnostic accuracy and for predicting treatment response.

METHODS

The mRNAs expression data of CC patients and cellular senescence-related genes were obtained from the Cancer Genome Atlas (TCGA) and CellAge databases, respectively. Differentially expressed genes (DEGs) of senescence related genes between tumor and normal tissues were used for Least absolute shrinkage and selection operator (LASSO) regression to construct a prognostic model. Univariate and LASSO regression analyses were applied to establish a predictive nomogram. The performance of the nomogram were evaluated by Kaplan-Meier curve, receiver operating characteristic (ROC), Harrell's concordance index (C-index), and calibration curve. GSE44001 and GSE52903 were used for external validation.

RESULTS

We established a cellular senescence-related genes-based stratified model, and a multivariable-based nomogram, which could accurately predict the prognosis of CC patients in the TCGA database. The Kaplan-Meier curve indicated that patients in the low-risk group had considerably better overall survival (OS, P =2.021e-05). The area under the ROC curve (AUC) of this model was 0.743 for OS. Multivariate analysis found that the 6-gene risk signature (HR=3.166, 95%CI: 1.660-6.041, P<0.001) was an independent risk factor for CC patients. We then designed an OS-associated nomogram that included the risk signature and clinicopathological factors. The AUC reached 0.860 for predicting 5-year OS. The nomogram showed excellent consistency between the predictions and actual survival observations. Two external GEO validations were corresponding to the gene expression pattern in TCGA.

CONCLUSIONS

Our results suggested a six-senescence related signature and established a prognostic nomogram that reliably predicted the overall survival for CC. These findings may be beneficial to personalized treatment and medical decision-making.