High-level Sp1 is Associated with Proliferation, Invasion, and Poor Prognosis in Astrocytoma

An anti-neoplastic tale of metformin through its transport

Metformin is an attractive candidate drug among all the repurposed drugs for cancer. Extensive preclinical and clinical research has evaluated its efficacy in cancer therapy, revealing a mixed outcome in clinical settings. To fully exploit metformin's therapeutic potential, understanding cellular factors relevant to its transport and accumulation in cancer cells needs to be understood. This review highlights the relevance of metformin transporter status towards its anti-cancer potential. Metformin transporters are regulated at pre-transcriptional, transcriptional, and post-translational levels. Moreover, the tumour microenvironment can also influence metformin accumulation in cancer cells. Also, Metformin treatment can regulate its transporters by altering global DNA methylation, protein acetylation, and transcription factors. Importantly, metformin transporters not only influence chemotherapeutic drug toxicity but are also associated with the prognosis and survival of individuals having cancer. Strategic decisions based on the expression and regulation of metformin transporters holds promise for its therapeutic implications and relevance.

Folic acid blocks ferroptosis induced by cerebral ischemia and reperfusion through regulating folate hydrolase transcriptional adaptive program

Cerebral ischemia-reperfusion (I/R) injury is notably linked with folic acid (FA) deficiency. The aim of our investigation was to explore the effects and underlying mechanisms by which FA mitigates I/R, specifically through regulating the GCPII transcriptional adaptive program. Initially, we discovered that following cerebral I/R, levels of FA, methionine synthase (MTR), and methylenetetrahydrofolate reductase (MTHFR) were decreased, while GCPII expression was elevated. Secondly, administering FA could mitigate cognitive impairment and neuronal damage induced by I/R. Thirdly, the mechanism of FA supplementation involved suppressing the transcriptional factor Sp1, subsequently inhibiting GCPII transcription, reducing Glu content, obstructing cellular ferroptosis, and alleviating cerebral I/R injury. In summary, our data demonstrate that FA affords protection against cerebral I/R injury by inhibiting the GCPII transcriptional adaptive response. These findings unveil that targeting GCPII might be a viable therapeutic strategy for cerebral I/R.

Specificity Proteins (Sp) and Cancer

The specificity protein (Sp) transcription factors (TFs) Sp1, Sp2, Sp3 and Sp4 exhibit structural and functional similarities in cancer cells and extensive studies of Sp1 show that it is a negative prognostic factor for patients with multiple tumor types. In this review, the role of Sp1, Sp3 and Sp4 in the development of cancer and their regulation of pro-oncogenic factors and pathways is reviewed. In addition, interactions with non-coding RNAs and the development of agents that target Sp transcription factors are also discussed. Studies on normal cell transformation into cancer cell lines show that this transformation process is accompanied by increased levels of Sp1 in most cell models, and in the transformation of muscle cells into rhabdomyosarcoma, both Sp1 and Sp3, but not Sp4, are increased. The pro-oncogenic functions of Sp1, Sp3 and Sp4 in cancer cell lines were studied in knockdown studies where silencing of each individual Sp TF decreased cancer growth, invasion and induced apoptosis. Silencing of an individual Sp TF was not compensated for by the other two and it was concluded that Sp1, Sp3 and Sp4 are examples of non-oncogene addicted genes. This conclusion was strengthened by the results of Sp TF interactions with non-coding microRNAs and long non-coding RNAs where Sp1 contributed to pro-oncogenic functions of Sp/non-coding RNAs. There are now many examples of anticancer agents and pharmaceuticals that induce downregulation/degradation of Sp1, Sp3 and Sp4, yet clinical applications of drugs specifically targeting Sp TFs are not being used. The application of agents targeting Sp TFs in combination therapies should be considered for their potential to enhance treatment efficacy and decrease toxic side effects.

High expression of NLRP12 predicts poor prognosis in patients with intracranial glioma

BACKGROUND

Intracranial gliomas are the most common primary central nervous system tumors in humans, and glioblastoma multiforme is the most malignant intracranial glioma. The nucleotide-binding domain leucine-rich repeat (NLR)-containing family are crucial regulators of inflammatory and innate immune responses. NLRP12 codes for the monarch-1 protein, which regulates immune responses in humans. Data from a next-generation sequencing database indicated that NLRP12 expression is increased in glioma cells. However, the relationship between NLRP12 levels and gliomas is unclear.

METHODS

To explore the role of NLRP12-related translation factors and proteins in glioma, we evaluated the clinical data and paraffin sections from glioma patients. The expression of NLRP12 was evaluated using immunohistochemical analysis, and clinical parameters were analyzed using chi-square and Kaplan-Meier survival tests.

RESULTS

The degree of malignancy and prognosis highly correlated with NLRP12 levels. In addition, the siRNA-mediated downregulation of NLRP12 in glioma cell lines decreased proliferation, invasion, and migration. The levels of VEGF, N-cadherin, and cyclin D1 were downregulated after knockdown of NRLP12 in glioma cell lines, as observed using western blotting in vitro. Knockdown of NLRP12 attenuated the tumor progression in vivo.

CONCLUSION

The expression of NLRP12 may be an independent prognostic factor and a potential target for the treatment of intracranial glioma.

Specificity Protein 1: A Protein With a Two-Sided Role in Ischemic Stroke

Stroke is one of the leading causes of death and disability worldwide. However, there is a lack of effective medications to speed up the recovery process. Ischemic stroke, as the result of cerebral infarction or cerebral artery narrowing, is accompanied by hemiplegia or impaired consciousness. There are many transcription factors involved in the development of this condition, whose alterations can influence or signal the prognostic outcomes of ischemic stroke. Among them, the augmented expression of specificity protein 1 (SP1) can participate in the progression of the disease by binding DNA to regulate the transcriptions of many genes. Different studies have provided different answers as to whether SP1 plays a positive or a negative role in ischemic stroke. On the one hand, SP1 can play a cytoprotective role as both an antioxidant and anti-apoptotic agent for neurons and glial cells. On the other hand, it can also damage neuronal cells by promoting inflammation and exacerbating brain edema. In this review, we highlight the roles of SP1 in ischemic stroke and shed light on the underlying mechanism.

Transcription factors specificity protein and nuclear receptor 4A1 in pancreatic cancer

Specificity protein (Sp) transcription factors (TFs) Sp1, Sp3 and Sp4, and the orphan nuclear receptor 4A1 (NR4A1) are highly expressed in pancreatic tumors and Sp1 is a negative prognostic factor for pancreatic cancer patient survival. Results of knockdown and overexpression of Sp1, Sp3 and Sp4 in pancreatic and other cancer lines show that these TFs are individually pro-oncogenic factors and loss of one Sp TF is not compensated by other members. NR4A1 is also a pro-oncogenic factor and both NR4A1 and Sp TFs exhibit similar functions in pancreatic cancer cells and regulate cell growth, survival, migration and invasion. There is also evidence that Sp TFs and NR4A1 regulate some of the same genes including survivin, epidermal growth factor receptor, PAX3-FOXO1, α5- and α6-integrins, β1-, β3- and β4-integrins; this is due to NR4A1 acting as a cofactor and mediating NR4A1/Sp1/4-regulated gene expression through GC-rich gene promoter sites. Several studies show that drugs targeting Sp downregulation or NR4A1 antagonists are highly effective inhibitors of Sp/NR4A1-regulated pathways and genes in pancreatic and other cancer cells, and the triterpenoid celastrol is a novel dual-acting agent that targets both Sp TFs and NR4A1.

SP1 Expression and the Clinicopathological Features of Tumors: A Meta-Analysis and Bioinformatics Analysis

Objective: Specificity protein 1 (SP1) plays a vital role to promote carcinogenesis in a variety of tumors, and its up-regulated expression is reported to be a hinter of poor prognosis of patients. We conducted this meta-analysis to elucidate the clinical significance and prognostic value of SP1 in malignant tumors. Methods: PubMed and Cochrane Library were searched for studies published between January 1, 2000 and June 1, 2020. The combined odds ratios (ORs) and hazard ratios (HRs) with 95% confidence intervals (95% CIs) were used to investigate the correlation of SP1 with clinical behaviors and prognosis in patients with solid tumors. UALCAN was used to conduct bioinformatics analysis. Results: A total of 24 documents involving 2,739 patients were enrolled in our review. The random-effect model was used to perform this analysis due to the high level of heterogeneity. SP1 low expression was not conducive to lymph node metastasis (OR = 0.42; 95% CI: 0.28-0.64; p < 0.05), progression of TNM stage (OR = 0.34; 95% CI: 0.20-0.57; p < 0.05) and tumor infiltration (OR = 0.33; 95% CI: 0.18-0.60; p < 0.05). Elevated SP1 expression was connected with shorter survival time of patients with hepatocellular carcinoma, pancreatic cancer, gastric cancer and esophageal cancer (HR = 1.95; 95% CI: 1.16-3.28; p < 0.05). According to UALCAN database, breast cancer, ovarian cancer, colon cancer and lung adenocarcinoma display an elevated SP1 expression in comparison with normal tissues. Kaplan-Meier survival plots indicate SP1 mRNA level has negative effects on prognosis of liver hepatocellular carcinoma and brain lower grade glioma. Conclusion: SP1 was associated with lymph node metastasis, TNM stage and depth of invasion, and indicated poor clinical outcome, which brought new insights on the potential candidacy of SP1 in clinical usage.

Metastasis to lymph nodes around the vascular tie worsens long-term oncological outcomes following complete mesocolic excision and conventional colectomy for right-sided colon cancer

BACKGROUND

Oncologic outcomes after complete mesocolic excision (CME) in colon cancer are under investigation. The aim of our study was to compare CME and conventional colectomy (CC) in terms of pathological and oncological outcomes for right colon cancer and to evaluate the impact of lymph node metastasis around the vascular tie on survival.

METHODS

Consecutive patients with right colon cancer who had CME or CC between January 2011 and August 2018 at two specialized centers in Turkey were included. Statistical analyses were performed with respect to demographic characteristics, operative and pathologic outcomes, harvested and metastatic lymph nodes around the vascular tie (LNVT), recurrences, and survival.

RESULTS

There were 91 patients in the CME group (58 males, mean age 64 ± 16 years) and 192 patients in the CC group (96 males, mean age 66 ± 14 years). The mean number of harvested lymph nodes (CME: 42 ± 15 vs CC: 34 ± 13, p = 0.01) and LNVT were higher in the CME group (CME: 3.2 ± 2.2 vs CC: 2.4 ± 1.6, p = 0.001). LNVT metastases were 7.7% and 8.3% in the CME and CC groups, respectively (p = 0.85). Three-year overall and disease-free survival rates were 96.4% and 90.9% in the CME group and 90.4% and 87.6% in the CC group in stage I-III patients (p > 0.05). In stage III patients, the 3-year overall survival (92.5% vs 63.5%, p = 0.03) and disease-free survival (85.6% vs 52.1%, p = 0.008) were significantly better in LNVT-negative patients than in LNVT-positive patients.

CONCLUSION

LNVT metastasis seems to be the key factor associated with poor disease-free and overall survival in right colon cancer regardless of the radicality of surgery.

A Novel 10-Gene Signature Predicts Poor Prognosis in Low Grade Glioma

AIM

Low grade glioma (LGG) is a lethal brain cancer with relatively poor prognosis in young adults. Thus, this study was performed to develop novel molecular biomarkers to effectively predict the prognosis of LGG patients and finally guide treatment decisions.

METHODS

survival-related genes were determined by Kaplan-Meier survival analysis and multivariate Cox regression analysis using the expression and clinical data of 506 LGG patients from The Cancer Genome Atlas (TCGA) database and independently validated in a Chinese Glioma Genome Atlas (CGGA) dataset. A prognostic risk score was established based on a linear combination of 10 gene expression levels using the regression coefficients of the multivariate Cox regression models. GSEA was performed to analyze the altered signaling pathways between the high and low risk groups stratified by median risk score.

RESULTS

We identified a total of 1489 genes significantly correlated with patients' prognosis in LGG. The top 5 protective genes were DISP2, CKMT1B, AQP7, GPR162 and CHGB, the top 5 risk genes were SP1, EYA3, ZSCAN20, ITPRIPL1 and ZNF217 in LGG. The risk score was predictive of poor overall survival and relapse-free survival in LGG patients. Pathways of small cell lung cancer, pathways in cancer, chronic myeloid leukemia, colorectal cancer were the top 4 most enriched pathways in the high risk group. SP1, EYA3, ZSCAN20, ITPRIPL1, ZNF217 and GPR162 were significantly up-regulated, while DISP2, CKMT1B, AQP7 were down-regulated in 523 LGG tissues as compared to 1141 normal brain controls.

CONCLUSIONS

The 10-gene signature may become novel prognostic and diagnostic biomarkers to considerably improve the prognostic prediction in LGG.

N-Butanol Fraction of Wenxia Formula Extract Inhibits the Growth and Invasion of Non-Small Cell Lung Cancer by Down-Regulating Sp1-Mediated MMP2 Expression

Lung cancer is the most commonly diagnosed cancer and the leading cause of cancer death. It is necessary to develop effective anti-lung cancer therapeutics. Wenxia Formula (WXF), an empirical traditional Chinese herbal formula, has been reported to have significant antitumor activity. In this study, to further clarify the material basis of the anti-tumor effect of WXF, we investigated the cytotoxic effect of the N-butanol fraction of Wenxia Formula extract (NWXF) against two lung cancer and one normal human cell lines. The chemical profile of NWXF was characterized by UPLC/Q-TOF-MS analysis and a total of 201 compounds with mzCloud Best Match of greater than 70 were identified by using the online database mzCloud. To address the functional role of NWXF, we assessed cell proliferation, migration and invasion capabilities. Subcutaneous xenografts were constructed to determine the effect of NWXF in vivo. The results showed that NWXF effectively inhibited the proliferation and migration of non-small cell lung cancer (NSCLC) cells with little toxic effects on human bronchial epithelial cells. Meanwhile, orally administered NWXF exhibited prominent dose-dependent anti-tumor efficacy in vivo. Mechanistically, NWXF significantly downregulated MMP9 and Sp1-mediated MMP2 expression. In conclusion, NWXF might be a promising candidate for treatment of human lung cancer.

MYCT1 inhibits the EMT and migration of laryngeal cancer cells via the SP1/miR-629-3p/ESRP2 pathway

MYCT1 has an inhibitory effect on the migration of laryngeal cancer cells, although the underlying molecular mechanism remains unknown. In this study, we aimed to explore the mechanism of MYCT1 in the epithelial-mesenchymal transition (EMT) and migration of laryngeal cancer cells. We found that MYCT1 significantly decreased the expression of miR-629-3p but increased the expression of ESRP2 in laryngeal cancer cells. The expression of miR-629-3p and ESRP2 in laryngeal cancer tissues showed significantly positive and negative correlations with patient metastasis, respectively. miR-629-3p was confirmed to repress the expression of ESRP2 by targeting its 3'UTR. SP1 was verified to be a direct transcription factor for miR-629-3p and a downstream target of MYCT1. Moreover, MYCT1 inhibited the EMT and migration of laryngeal cancer cells through the SP1/miR-629-3p/ESRP2 pathway. Taken together, our results establish a novel MYCT1 signaling pathway in the EMT and migration of laryngeal cancer cells, thus providing important insights for further studying the pathway in the diagnosis and treatment of laryngeal cancer.

The SP1-12LOX axis promotes chemoresistance and metastasis of ovarian cancer

BACKGROUND

Ovarian cancer is the most lethal gynecologic cancer. Chemoresistance, especially platinum-resistance, is closely related to metastasis of ovarian cancer, however, the molecular basis by which links chemoresistance and metastasis remains vague. Disordered arachidonic acid (AA) metabolism has been shown to play an important role in the advanced ovarian cancer. This study aimed to explore the underlying mechanism involving eicosanoid metabolism that controlling chemoresistance and metastasis of ovarian cancer.

METHODS

Cisplatin (DDP)-resistant SKOV3 (SKOV3-R) cells were constantly induced. Ultra-high-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was performed to determine the AA metabolism in SKOV3 and SKOV3-R cells. Half maximal inhibitory concentration (IC50) and percentage of cell viability were tested using cell counting kit 8 (CCK-8). Realtime quantitative PCR (qPCR) and immunohistochemistry (IHC) were used to evaluate indicated genes and proteins respectively. Bioinformatic analysis and chromatin immunoprecipitation (ChIP) were performed to predict and identify the co-transcription factor of interest genes. Tumor growth and metastasis in the liver were assessed with nude mice by subcutaneously injection of SKOV3-R cells.

RESULTS

SKOV3-R cells expressed higher multidrug resistance-associated proteins (MRPs) MRP1 and MRP4. They showed enhanced metastatic ability and produced increased AA-derived eicosanoids. Mechanistically, MRPs, epithelial mesenchymal transition (EMT) markers Snail and Slug, as well as key enzymes involved in AA-metabolism including 12-lipoxygenase (12LOX) were transcribed by the mutual transcription factor SP1 which was consistently upregulated in SKOV3-R cells. Inhibition of SP1 or 12LOX sensitized SKOV3-R cells to DDP and impaired metastasis in vitro and in vivo.

CONCLUSION

Our results reveal that SP1-12LOX axis signaling plays a key role in DDP-resistance and metastasis, which provide a new therapeutic target for ovarian cancer.

Understanding the Role of the Transcription Factor Sp1 in Ovarian Cancer: from Theory to Practice

Ovarian cancer (OC) is one of the deadliest cancers among women contributing to high risk of mortality, mainly owing to delayed detection. There is no specific biomarker for its detection in early stages. However, recent findings show that over-expression of specificity protein 1 (Sp1) is involved in many OC cases. The ubiquitous transcription of Sp1 apparently mediates the maintenance of normal and cancerous biological processes such as cell growth, differentiation, angiogenesis, apoptosis, cellular reprogramming and tumorigenesis. Sp1 exerts its effects on cellular genes containing putative GC-rich Sp1-binding site in their promoters. A better understanding of the mechanisms underlying Sp1 transcription factor (TF) regulation and functions in OC tumorigenesis could help identify novel prognostic markers, to target cancer stem cells (CSCs) by following cellular reprogramming and enable the development of novel therapies for future generations. In this review, we address the structure, function, and biology of Sp1 in normal and cancer cells, underpinning the involvement of Sp1 in OC tumorigenesis. In addition, we have highlighted the influence of Sp1 TF in cellular reprogramming of iPSCs and how it plays a role in controlling CSCs. This review highlights the drugs targeting Sp1 and their action on cancer cells. In conclusion, we predict that research in this direction will be highly beneficial for OC treatment, and chemotherapeutic drugs targeting Sp1 will emerge as a promising therapy for OC.

Oligonucleotide Therapeutics as a New Class of Drugs for Malignant Brain Tumors: Targeting mRNAs, Regulatory RNAs, Mutations, Combinations, and Beyond

Malignant brain tumors are rapidly progressive and often fatal owing to resistance to therapies and based on their complex biology, heterogeneity, and isolation from systemic circulation. Glioblastoma is the most common and most aggressive primary brain tumor, has high mortality, and affects both children and adults. Despite significant advances in understanding the pathology, multiple clinical trials employing various treatment strategies have failed. With much expanded knowledge of the GBM genome, epigenome, and transcriptome, the field of neuro-oncology is getting closer to achieve breakthrough-targeted molecular therapies. Current developments of oligonucleotide chemistries for CNS applications make this new class of drugs very attractive for targeting molecular pathways dysregulated in brain tumors and are anticipated to vastly expand the spectrum of currently targetable molecules. In this chapter, we will overview the molecular landscape of malignant gliomas and explore the most prominent molecular targets (mRNAs, miRNAs, lncRNAs, and genomic mutations) that provide opportunities for the development of oligonucleotide therapeutics for this class of neurologic diseases. Because malignant brain tumors focally disrupt the blood-brain barrier, this class of diseases might be also more susceptible to systemic treatments with oligonucleotides than other neurologic disorders and, thus, present an entry point for the oligonucleotide therapeutics to the CNS. Nevertheless, delivery of oligonucleotides remains a crucial part of the treatment strategy. Finally, synthetic gRNAs guiding CRISPR-Cas9 editing technologies have a tremendous potential to further expand the applications of oligonucleotide therapeutics and take them beyond RNA targeting.