p53 deficiency induces MTHFD2 transcription to promote cell proliferation and restrain DNA damage

Cancer cells acquire metabolic reprogramming to satisfy their high biogenetic demands, but little is known about how metabolic remodeling enables cancer cells to survive stress associated with genomic instability. Here, we show that the mitochondrial methylenetetrahydrofolate dehydrogenase (MTHFD2) is transcriptionally suppressed by p53, and its up-regulation by p53 inactivation leads to increased folate metabolism, de novo purine synthesis, and tumor growth in vivo and in vitro. Moreover, MTHFD2 unexpectedly promotes nonhomologous end joining in response to DNA damage by forming a complex with PARP3 to enhance its ribosylation, and the introduction of a PARP3-binding but enzymatically inactive MTHFD2 mutant (e.g., D155A) sufficiently prevents DNA damage. Notably, MTHFD2 depletion strongly restrains p53-deficient cell proliferation and sensitizes cells to chemotherapeutic agents, indicating a potential role for MTHFD2 depletion in the treatment of p53-deficient tumors.

Download Full-text

KLF5 Is Crucial for Androgen-AR Signaling to Transactivate Genes and Promote Cell Proliferation in Prostate Cancer Cells

Cancers ◽

10.3390/cancers12030748 ◽

2020 ◽

Vol 12 (3) ◽

pp. 748 ◽

Cited By ~ 1

Author(s):

Juan Li ◽

Baotong Zhang ◽

Mingcheng Liu ◽

Xing Fu ◽

Xinpei Ci ◽

...

Keyword(s):

Prostate Cancer ◽

Cell Proliferation ◽

Cancer Cells ◽

Transcriptional Activity ◽

Prostate Cancer Cells ◽

Normal Prostate ◽

Promote Cell Proliferation ◽

Therapeutic Opportunity

Androgen/androgen receptor (AR) signaling drives both the normal prostate development and prostatic carcinogenesis, and patients with advanced prostate cancer often develop resistance to androgen deprivation therapy. The transcription factor Krüppel-like factor 5 (KLF5) also regulates both normal and cancerous development of the prostate. In this study, we tested whether and how KLF5 plays a role in the function of AR signaling in prostate cancer cells. We found that KLF5 is upregulated by androgen depending on AR in LNCaP and C4-2B cells. Silencing KLF5, in turn, reduced AR transcriptional activity and inhibited androgen-induced cell proliferation and tumor growth in vitro and in vivo. Mechanistically, KLF5 occupied the promoter of AR, and silencing KLF5 repressed AR transcription. In addition, KLF5 and AR physically interacted with each other to regulate the expression of multiple genes (e.g., MYC, CCND1 and PSA) to promote cell proliferation. These findings indicate that, while transcriptionally upregulated by AR signaling, KLF5 also regulates the expression and transcriptional activity of AR in androgen-sensitive prostate cancer cells. The KLF5-AR interaction could provide a therapeutic opportunity for the treatment of prostate cancer.

Download Full-text

LncRNA UCA1 promotes development of gastric cancer via the miR-145/MYO6 axis

Cellular & Molecular Biology Letters ◽

10.1186/s11658-021-00275-8 ◽

2021 ◽

Vol 26 (1) ◽

Author(s):

An Yang ◽

Xin Liu ◽

Ping Liu ◽

Yunzhang Feng ◽

Hongbo Liu ◽

...

Keyword(s):

Gastric Cancer ◽

Cell Proliferation ◽

Cancer Cells ◽

Cell Apoptosis ◽

Gastric Cancer Cell ◽

Gastric Cancer Cells ◽

Gastric Cancer Cell Lines ◽

Development Of Gastric Cancer

Abstract Background Long noncoding RNA (lncRNA), urothelial carcinoma-associated 1 (UCA1) is aberrantly expressed in multiple cancers and has been verified as an oncogene. However, the underlying mechanism of UCA1 in the development of gastric cancer is not fully understood. In the present study, we aimed to identify how UCA1 promotes gastric cancer development. Methods The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) data were used to analyze UCA1 and myosin VI (MYO6) expression in gastric cancer. Western blot and quantitative real-time PCR (QPCR) were performed to test the expression level of the UCA1/miR-145/MYO6 axis in gastric cancer cell lines and tissues. The roles of the UCA1/miR-145/MYO6 axis in gastric cancer in vitro and in vivo were investigated by CCK-8 assay, flow cytometry, siRNAs, immunohistochemistry, and a mouse xenograft model. The targeted relationship among UCA1, miR-145, and MYO6 was predicted using LncBase Predicted v.2 and TargetScan online software, and then verified by luciferase activity assay and RNA immunoprecipitation. Results UCA1 expression was higher but miR-145 expression was lower in gastric cancer cell lines or tissues, compared to the adjacent normal cell line or normal tissues. Function analysis verified that UCA1 promoted cell proliferation and inhibited cell apoptosis in the gastric cancer cells in vitro and in vivo. Mechanistically, UCA1 could bind directly to miR-145, and MYO6 was found to be a downstream target gene of miR-145. miR-145 mimics or MYO6 siRNAs could partly reverse the effect of UCA1 on gastric cancer cells. Conclusions UCA1 accelerated cell proliferation and inhibited cell apoptosis through sponging miR-145 to upregulate MYO6 expression in gastric cancer, indicating that the UCA1/miR-145/MYO6 axis may serve as a potential therapeutic target for gastric cancer.

Download Full-text

Knockdown CYP2S1 inhibits lung cancer cells proliferation and migration

Cancer Biomarkers ◽

10.3233/cbm-210189 ◽

2021 ◽

pp. 1-9

Author(s):

Huan Guo ◽

Baozhen Zeng ◽

Liqiong Wang ◽

Chunlei Ge ◽

Xianglin Zuo ◽

...

Keyword(s):

Lung Cancer ◽

Cell Proliferation ◽

Cell Growth ◽

Cancer Cells ◽

Molecular Mechanisms ◽

Lung Cancer Cells ◽

Invasion And Migration ◽

And Migration

BACKGROUND: The incidence of lung cancer in Yunnan area ranks firstly in the world and underlying molecular mechanisms of lung cancer in Yunnan region are still unclear. We screened a novel potential oncogene CYP2S1 used mRNA microassay and bioinformation database. The function of CYP2S1 in lung cancer has not been reported. OBJECTIVE: To investigate the functions of CYP2S1 in lung cancer. METHODS: Immunohistochemistry and Real-time PCR were used to verify the expression of CYP2S1. Colony formation and Transwell assays were used to determine cell proliferation, invasion and migration. Xenograft assays were used to detected cell growth in vivo. RESULTS: CYP2S1 is significantly up-regulated in lung cancer tissues and cells. Knockdown CYP2S1 in lung cancer cells resulted in decrease cell proliferation, invasion and migration in vitro. Animal experiments showed downregulation of CYP2S1 inhibited lung cancer cell growth in vivo. GSEA analysis suggested that CYP2S1 played functions by regulating E2F targets and G2M checkpoint pathway which involved in cell cycle. Kaplan-Meier analysis indicated that patients with high CYP2S1 had markedly shorter event overall survival (OS) time. CONCLUSIONS: Our data demonstrate that CYP2S1 exerts tumor suppressor function in lung cancer. The high expression of CYP2S1 is an unfavorable prognostic marker for patient survival.

Download Full-text

PAICS contributes to gastric carcinogenesis and participates in DNA damage response by interacting with histone deacetylase 1/2

Cell Death and Disease ◽

10.1038/s41419-020-2708-5 ◽

2020 ◽

Vol 11 (7) ◽

Author(s):

Nan Huang ◽

Chang Xu ◽

Liang Deng ◽

Xue Li ◽

Zhixuan Bian ◽

...

Keyword(s):

Dna Damage ◽

Histone Deacetylase ◽

Dna Damage Response ◽

De Novo ◽

Dna Damage Repair ◽

Histone Deacetylase 1 ◽

Damage Repair ◽

Damage Response

AbstractPhosphoribosylaminoimidazole carboxylase, phosphoribosylaminoimidazole succinocarboxamide synthetase (PAICS), an essential enzyme involved in de novo purine biosynthesis, is connected with formation of various tumors. However, the specific biological roles and related mechanisms of PAICS in gastric cancer (GC) remain unclear. In the present study, we identified for the first time that PAICS was significantly upregulated in GC and high expression of PAICS was correlated with poor prognosis of patients with GC. In addition, knockdown of PAICS significantly induced cell apoptosis, and inhibited GC cell growth both in vitro and in vivo. Mechanistic studies first found that PAICS was engaged in DNA damage response, and knockdown of PAICS in GC cell lines induced DNA damage and impaired DNA damage repair efficiency. Further explorations revealed that PAICS interacted with histone deacetylase HDAC1 and HDAC2, and PAICS deficiency decreased the expression of DAD51 and inhibited its recruitment to DNA damage sites by impairing HDAC1/2 deacetylase activity, eventually preventing DNA damage repair. Consistently, PAICS deficiency enhanced the sensitivity of GC cells to DNA damage agent, cisplatin (CDDP), both in vitro and in vivo. Altogether, our findings demonstrate that PAICS plays an oncogenic role in GC, which act as a novel diagnosis and prognostic biomarker for patients with GC.

Download Full-text

Inhibition of MCF-7 breast cancer cell proliferation by 5alpha-dihydrotestosterone; a role for p21(Cip1/Waf1)

Journal of Molecular Endocrinology ◽

10.1677/jme.0.0320793 ◽

2004 ◽

Vol 32 (3) ◽

pp. 793-810 ◽

Cited By ~ 47

Author(s):

MA Greeve ◽

RK Allan ◽

JM Harvey ◽

JM Bentel

Keyword(s):

Breast Cancer ◽

Cell Proliferation ◽

Cancer Cells ◽

Breast Cancer Cells ◽

S Phase ◽

Cyclin D3 ◽

P27 Kip1 ◽

Mcf 7

Androgens inhibit the growth of breast cancer cells in vitro and in vivo by mechanisms that remain poorly defined. In this study, treatment of asynchronously growing MCF-7 breast cancer cells with the androgen, 5alpha-dihydrotestosterone (DHT), was shown to inhibit cell proliferation and induce moderate increases in the proportion of G1 phase cells. Consistent with targeting the G1-S phase transition, DHT pretreatment of MCF-7 cultures impeded the serum-induced progression of G1-arrested cells into S phase and reduced the kinase activities of cyclin-dependent kinase (Cdk)4 and Cdk2 to less than 50% of controls within 3 days. DHT treatment was associated with greater than twofold increases in the levels of the Cdk inhibitor, p27(Kip1), while p21(Cip1/Waf1) protein levels remained unchanged. During the first 24 h of DHT treatment, levels of Cdk4-associated p21(Cip1/Waf1) and p27(Kip1) were reduced coinciding with decreased levels of Cdk4-associated cyclin D3. In contrast, DHT treatment caused increased accumulation of Cdk2-associated p21(Cip1/Waf1), with no significant alterations in levels of p27(Kip1) bound to Cdk2 complexes. These findings suggest that DHT reverses the Cdk4-mediated titration of p21(Cip1/Waf1) and p27(Kip1) away from Cdk2 complexes, and that the increased association of p21(Cip1/Waf1) with Cdk2 complexes in part mediates the androgen-induced growth inhibition of breast cancer cells.

Download Full-text

HPV-18 E6 Oncoprotein and Its Spliced Isoform E6*I Regulate the Wnt/β-Catenin Cell Signaling Pathway through the TCF-4 Transcriptional Factor

International Journal of Molecular Sciences ◽

10.3390/ijms19103153 ◽

2018 ◽

Vol 19 (10) ◽

pp. 3153 ◽

Cited By ~ 6

Author(s):

J. Muñoz-Bello ◽

Leslie Olmedo-Nieva ◽

Leonardo Castro-Muñoz ◽

Joaquín Manzo-Merino ◽

Adriana Contreras-Paredes ◽

...

Keyword(s):

Cervical Cancer ◽

Cell Proliferation ◽

Signaling Pathway ◽

Transcriptional Activation ◽

Target Genes ◽

Promote Cell Proliferation ◽

E6 And E7 ◽

Hpv 18

The Wnt/β-catenin signaling pathway regulates cell proliferation and differentiation and its aberrant activation in cervical cancer has been described. Persistent infection with high risk human papillomavirus (HR-HPV) is the most important factor for the development of this neoplasia, since E6 and E7 viral oncoproteins alter cellular processes, promoting cervical cancer development. A role of HPV-16 E6 in Wnt/β-catenin signaling has been proposed, although the participation of HPV-18 E6 has not been previously studied. The aim of this work was to investigate the participation of HPV-18 E6 and E6*I, in the regulation of the Wnt/β-catenin signaling pathway. Here, we show that E6 proteins up-regulate TCF-4 transcriptional activity and promote overexpression of Wnt target genes. In addition, it was demonstrated that E6 and E6*I bind to the TCF-4 (T cell factor 4) and β-catenin, impacting TCF-4 stabilization. We found that both E6 and E6*I proteins interact with the promoter of Sp5, in vitro and in vivo. Moreover, although differences in TCF-4 transcriptional activation were found among E6 intratype variants, no changes were observed in the levels of regulated genes. Furthermore, our data support that E6 proteins cooperate with β-catenin to promote cell proliferation.

Download Full-text

Arginine-deprivation–induced oxidative damage sterilizes Mycobacterium tuberculosis

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1808874115 ◽

2018 ◽

Vol 115 (39) ◽

pp. 9779-9784 ◽

Cited By ~ 22

Author(s):

Sangeeta Tiwari ◽

Andries J. van Tonder ◽

Catherine Vilchèze ◽

Vitor Mendes ◽

Sherine E. Thomas ◽

...

Keyword(s):

Oxidative Stress ◽

Dna Damage ◽

Mycobacterium Tuberculosis ◽

De Novo ◽

Target Space ◽

Biosynthesis Pathway ◽

Arginine Biosynthesis ◽

Arginine Deprivation

Reactive oxygen species (ROS)-mediated oxidative stress and DNA damage have recently been recognized as contributing to the efficacy of most bactericidal antibiotics, irrespective of their primary macromolecular targets. Inhibitors of targets involved in both combating oxidative stress as well as being required for in vivo survival may exhibit powerful synergistic action. This study demonstrates that the de novo arginine biosynthetic pathway in Mycobacterium tuberculosis (Mtb) is up-regulated in the early response to the oxidative stress-elevating agent isoniazid or vitamin C. Arginine deprivation rapidly sterilizes the Mtb de novo arginine biosynthesis pathway mutants ΔargB and ΔargF without the emergence of suppressor mutants in vitro as well as in vivo. Transcriptomic and flow cytometry studies of arginine-deprived Mtb have indicated accumulation of ROS and extensive DNA damage. Metabolomics studies following arginine deprivation have revealed that these cells experienced depletion of antioxidant thiols and accumulation of the upstream metabolite substrate of ArgB or ArgF enzymes. ΔargB and ΔargF were unable to scavenge host arginine and were quickly cleared from both immunocompetent and immunocompromised mice. In summary, our investigation revealed in vivo essentiality of the de novo arginine biosynthesis pathway for Mtb and a promising drug target space for combating tuberculosis.

Download Full-text

Maximal killing of lymphoma cells by DNA damage–inducing therapy requires not only the p53 targets Puma and Noxa, but also Bim

Blood ◽

10.1182/blood-2010-04-280818 ◽

2010 ◽

Vol 116 (24) ◽

pp. 5256-5267 ◽

Cited By ~ 65

Author(s):

Lina Happo ◽

Mark S. Cragg ◽

Belinda Phipson ◽

Jon M. Haga ◽

Elisa S. Jansen ◽

...

Keyword(s):

Dna Damage ◽

Drug Resistance ◽

Target Genes ◽

B Cell Lymphoma ◽

Chemotherapeutic Agents ◽

Lymphoid Cells ◽

Lymphoma Cells ◽

P53 Target Genes

Abstract DNA-damaging chemotherapy is the backbone of cancer treatment, although it is not clear how such treatments kill tumor cells. In nontransformed lymphoid cells, the combined loss of 2 proapoptotic p53 target genes, Puma and Noxa, induces as much resistance to DNA damage as loss of p53 itself. In Eμ-Myc lymphomas, however, lack of both Puma and Noxa resulted in no greater drug resistance than lack of Puma alone. A third B-cell lymphoma-2 homology domain (BH)3-only gene, Bim, although not a direct p53 target, was up-regulated in Eμ-Myc lymphomas incurring DNA damage, and knockdown of Bim levels markedly increased the drug resistance of Eμ-Myc/Puma−/−Noxa−/− lymphomas both in vitro and in vivo. Remarkably, c-MYC–driven lymphoma cell lines from Noxa−/−Puma−/−Bim−/− mice were as resistant as those lacking p53. Thus, the combinatorial action of Puma, Noxa, and Bim is critical for optimal apoptotic responses of lymphoma cells to 2 commonly used DNA-damaging chemotherapeutic agents, identifying Bim as an additional biomarker for treatment outcome in the clinic.

Download Full-text

AXL and CAV-1 play a role for MTH1 inhibitor TH1579 sensitivity in cutaneous malignant melanoma

Cell Death and Differentiation ◽

10.1038/s41418-019-0488-1 ◽

2020 ◽

Vol 27 (7) ◽

pp. 2081-2098 ◽

Cited By ~ 3

Author(s):

Ishani Das ◽

Helge Gad ◽

Lars Bräutigam ◽

Linda Pudelko ◽

Rainer Tuominen ◽

...

Keyword(s):

Cell Proliferation ◽

Dna Damage ◽

Cell Death ◽

Malignant Melanoma ◽

Braf Inhibitor ◽

Mitotic Arrest ◽

Cutaneous Malignant Melanoma ◽

Clinical Samples

AbstractCutaneous malignant melanoma (CMM) is the deadliest form of skin cancer and clinically challenging due to its propensity to develop therapy resistance. Reactive oxygen species (ROS) can induce DNA damage and play a significant role in CMM. MTH1 protein protects from ROS damage and is often overexpressed in different cancer types including CMM. Herein, we report that MTH1 inhibitor TH1579 induced ROS levels, increased DNA damage responses, caused mitotic arrest and suppressed CMM proliferation leading to cell death both in vitro and in an in vivo xenograft CMM zebrafish disease model. TH1579 was more potent in abrogating cell proliferation and inducing cell death in a heterogeneous co-culture setting when compared with CMM standard treatments, vemurafenib or trametinib, showing its broad anticancer activity. Silencing MTH1 alone exhibited similar cytotoxic effects with concomitant induction of mitotic arrest and ROS induction culminating in cell death in most CMM cell lines tested, further emphasizing the importance of MTH1 in CMM cells. Furthermore, overexpression of receptor tyrosine kinase AXL, previously demonstrated to contribute to BRAF inhibitor resistance, sensitized BRAF mutant and BRAF/NRAS wildtype CMM cells to TH1579. AXL overexpression culminated in increased ROS levels in CMM cells. Moreover, silencing of a protein that has shown opposing effects on cell proliferation, CAV-1, decreased sensitivity to TH1579 in a BRAF inhibitor resistant cell line. AXL-MTH1 and CAV-1-MTH1 mRNA expressions were correlated as seen in CMM clinical samples. Finally, TH1579 in combination with BRAF inhibitor exhibited a more potent cell killing effect in BRAF mutant cells both in vitro and in vivo. In summary, we show that TH1579-mediated efficacy is independent of BRAF/NRAS mutational status but dependent on the expression of AXL and CAV-1.

Download Full-text

Triptolide suppresses IDH1-mutated malignancy via Nrf2-driven glutathione metabolism

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1913633117 ◽

2020 ◽

Vol 117 (18) ◽

pp. 9964-9972 ◽

Cited By ~ 12

Author(s):

Di Yu ◽

Yang Liu ◽

Yiqiang Zhou ◽

Victor Ruiz-Rodado ◽

Mioara Larion ◽

...

Keyword(s):

Reactive Oxygen Species ◽

De Novo ◽

Synthetic Lethality ◽

Reactive Oxygen ◽

Metabolic Reprogramming ◽

Glutathione Metabolism ◽

Oxygen Species ◽

Genetic Abnormality

Isocitrate dehydrogenase (IDH) mutation is a common genetic abnormality in human malignancies characterized by remarkable metabolic reprogramming. Our present study demonstrated that IDH1-mutated cells showed elevated levels of reactive oxygen species and higher demands on Nrf2-guided glutathione de novo synthesis. Our findings showed that triptolide, a diterpenoid epoxide from Tripterygium wilfordii, served as a potent Nrf2 inhibitor, which exhibited selective cytotoxicity to patient-derived IDH1-mutated glioma cells in vitro and in vivo. Mechanistically, triptolide compromised the expression of GCLC, GCLM, and SLC7A11, which disrupted glutathione metabolism and established synthetic lethality with reactive oxygen species derived from IDH1 mutant neomorphic activity. Our findings highlight triptolide as a valuable therapeutic approach for IDH1-mutated malignancies by targeting the Nrf2-driven glutathione synthesis pathway.

Download Full-text