• Title/Summary/Keyword: Tumor suppressor gene

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Tazarotene-Induced Gene 1 Interacts with DNAJC8 and Regulates Glycolysis in Cervical Cancer Cells

  • Wang, Chun-Hua;Shyu, Rong-Yaun;Wu, Chang-Chieh;Chen, Mao-Liang;Lee, Ming-Cheng;Lin, Yi-Yin;Wang, Lu-Kai;Jiang, Shun-Yuan;Tsai, Fu-Ming
    • Molecules and Cells
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    • v.41 no.6
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    • pp.562-574
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    • 2018
  • The tazarotene-induced gene 1 (TIG1) protein is a retinoidinducible growth regulator and is considered a tumor suppressor. Here, we show that DnaJ heat shock protein family member C8 (DNAJC8) is a TIG1 target that regulates glycolysis. Ectopic DNAJC8 expression induced the translocation of pyruvate kinase M2 (PKM2) into the nucleus, subsequently inducing glucose transporter 1 (GLUT1) expression to promote glucose uptake. Silencing either DNAJC8 or PKM2 alleviated the upregulation of GLUT1 expression and glucose uptake induced by ectopic DNAJC8 expression. TIG1 interacted with DNAJC8 in the cytosol, and this interaction completely blocked DNAJC8-mediated PKM2 translocation and inhibited glucose uptake. Furthermore, increased glycose uptake was observed in cells in which TIG1 was silenced. In conclusion, TIG1 acts as a pivotal repressor of DNAJC8 to enhance glucose uptake by partially regulating PKM2 translocation.

Disruption of the Tff1 gene in mice using CRISPR/Cas9 promotes body weight reduction and gastric tumorigenesis

  • Kim, Hyejeong;Jeong, Haengdueng;Cho, Yejin;Lee, Jaehoon;Nam, Ki Taek;Lee, Han-Woong
    • Laboraroty Animal Research
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    • v.34 no.4
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    • pp.257-263
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    • 2018
  • Trefoil factor 1 (TFF1, also known as pS2) is strongly expressed in the gastrointestinal mucosa and plays a critical role in the differentiation of gastric glands. Since approximately 50% of all human gastric cancers are associated with decreased TFF1 expression, it is considered a tumor suppressor gene. Tff1 deficiency in mice results in histological changes in the antral and pyloric gastric mucosa, with severe hyperplasia and dysplasia of epithelial cells, resulting in the development of antropyloric adenoma. Here, we generated Tff1-knockout (KO) mice, without a neomycin resistant ($Neo^R$) cassette, using the clustered regularly interspaced short palindromic repeats/CRISPR-associated nuclease 9 (CRSIPR/Cas9) system. Though our Tff1-KO mice showed phenotypes very similar to the previous embryonic stem (ES)-cell-based KO mice, they differed from the previous reports in that a reduction in body weight was observed in males. These results demonstrate that these newly established Tff1-KO mice are useful tools for investigating genetic and environmental factors influencing gastric cancer, without the effects of artificial gene insertion. Furthermore, these findings suggest a novel hypothesis that Tff1 expression influences gender differences.

No Relationship between the Amount of DNA Damage and the Level of hMLH1 and RASSF1A Gene Expression in Bladder Cancer Cells Treated with Cisplatin and Gemcitabine

  • de Camargo, Elaine Aparecida;da Silva, Glenda Nicioli;Gobette, Camila Pereira;de Castro Marcondes, Joao Paulo;Salvadori, Daisy Maria Favero
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.10
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    • pp.5941-5948
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    • 2013
  • Tumor response to antineoplastic drugs is not always predictable. This is also true for bladder carcinoma, a highly recurrent neoplasia. Currently, the combination of cisplatin and gemcitabine is well accepted as a standard protocol for treating bladder carcinoma. However, in some cases, this treatment protocol causes harmful side effects. Therefore, we investigated the roles of the genes TP53, RASSF1A (a tumor suppressor gene) and hMLH1 (a gene involved in the mismatch repair pathway) in cell susceptibility to cisplatin/gemcitabine treatment. Two bladder transitional carcinoma cell (TCC) lines, RT4 (wild-type TP53) and 5637 (mutated TP53), were used in this study. First, we evaluated whether the genotoxic potential of cisplatin/gemcitabine was dependent on TP53 status. Then, we evaluated whether the two antineoplastic drugs modulated RASSF1A and hMLH1 expression in the two cell lines. Increased DNA damage was observed in both cell lines after treatment with cisplatin or gemcitabine and with the two drugs simultaneously, as depicted by the comet assay. A lack of RASSF1A expression and hypermethylation of its promoter were observed before and after treatment in both cell lines. On the other hand, hMLH1 downregulation, unrelated to methylation status, was observed in RT4 cells after treatment with cisplatin or with cisplatin and gemcitabine simultaneously (wild-type TP53); in 5637 cells, hMLH1 was upregulated only after treatment with gemcitabine. In conclusion, the three treatment protocols were genotoxic, independent of TP53 status. However, cisplatin was the most effective, causing the highest level of DNA damage in both wild-type and mutated TP53 cells. Gemcitabine was the least genotoxic agent in both cell lines. Furthermore, no relationship was observed between the amount of DNA damage and the level of hMLH1 and RASSF1A expression. Therefore, other alternative pathways might be involved in cisplatin and gemcitabine genotoxicity in these two bladder cancer cell lines.

Transforming growth factor beta receptor II polymorphisms are associated with Kawasaki disease

  • Choi, Yu-Mi;Shim, Kye-Sik;Yoon, Kyung-Lim;Han, Mi-Young;Cha, Sung-Ho;Kim, Su-Kang;Jung, Joo-Ho
    • Clinical and Experimental Pediatrics
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    • v.55 no.1
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    • pp.18-23
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    • 2012
  • Purpose: Transforming growth factor beta receptor 2 ($TGFBR2$) is a tumor suppressor gene that plays a role in the differentiation of striated cells and remodeling of coronary arteries. Single nucleotide polymorphisms (SNPs) of this gene are associated with Marfan syndrome and sudden death in patients with coronary artery disease. Cardiovascular remodeling and T cell activation of $TGFBR2$ gene suggest that the $TGFBR2$ gene SNPs are related to the pathogenesis of Kawasaki disease (KD) and coronary artery lesion (CAL). Methods: The subjects were 105 patients with KD and 500 healthy adults as controls. Mean age of KD group was 32 months age and 26.6% of those had CAL. We selected $TGFBR2$ gene SNPs from serum and performed direct sequencing. Results: The sequences of the eleven SNPs in the $TGFBR2$ gene were compared between the KD group and controls. Three SNPs (rs1495592, rs6550004, rs795430) were associated with development of KD ($P$=0.019, $P$=0.026, $P$=0.016, respectively). One SNP (rs1495592) was associated with CAL in KD group ($P$=0.022). Conclusion: Eleven SNPs in $TGFBR2$ gene were identified at that time the genome wide association. But, with the change of the data base, only six SNPs remained associated with the $TGFBR2$ gene. One of the six SNPs (rs6550004) was associated with development of KD. One SNP associated with CAL (rs1495592) was disassociated from the $TGFBR2$ gene. The other five SNPs were not functionally identified, but these SNPs are notable because the data base is changing. Further studies involving larger group of patients with KD are needed.

Photodamage to Double-stranded DNA by Xanthone Analogues Increases Exponentially with Their HOMO Energies

  • Hirakawa, Kazutaka;Yoshida, Mami;Oikawa, Shinji;Kawanishi, Shosuke
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.488-490
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    • 2002
  • DNA photodamage mediated by photosensitizers are believed to play an important role in solar UVA carcinogenesis. We investigated the relationship between the DNA-damaging abilities of photoexcited xanthone analogues (as photosensitizers) and their highest occupied molecular orbital (HOMO) energies. DNA damage was examined using /sup 32/P-labeled DNA fragments obtained from the p53 tumor suppressor gene. These compounds induced DNA photodamage in a similar manner, and the extents of DNA damage were following order: xanthone> thioxanthone > acridone. Photoexcited xanthone caused nucleobase oxidation specifically at 5'-G of GG sequence in double-stranded DNA. An oxidative product of 2'-deoxyguanosine, 8-hydroxy-2'-deoxyguanosine (8-OHdG), was detected, and the amount was decreased by DNA denaturation. These findings suggest that photoexcited xanthone generates 8-OHdG at 5'-G of GG in double-stranded DNA through electron transfer. The calculated HOMO energies of these photosensitizers decreased in the following order: xanthone> thioxanthone > acridone. This study has demonstrated that DNA-damaging abilities of these photosensitizers increased exponentially with an increase in their HOMO energies.

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Birt-Hogg-Dubé Syndrome Manifesting as Spontaneous Pneumothorax: A Novel Mutation of the Folliculin Gene

  • Kim, Kyung Soo;Choi, Hang Jun;Jang, Woori;Chae, Hyojin;Kim, Myungshin;Moon, Seok Whan
    • Journal of Chest Surgery
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    • v.50 no.5
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    • pp.386-390
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    • 2017
  • $Birt-Hogg-Dub{\acute{e}}$ syndrome (BHDS) is a rare disease with autosomal dominant inheritance that manifests through skin tumors, pulmonary cystic lesions, and renal tumors. A mutation of FLCN located on chromosome 17p11.2, which encodes a tumor-suppressor protein (folliculin), is responsible for the development of BHDS. We report the case of a patient presenting with spontaneous pneumothorax, in whom a familial genetic study revealed a novel nonsense mutation: $p.(Arg379^*)$ in FLCN.

Evaluation of JC and Cytomegalo Viruses in Glioblastoma Tissue

  • Afshar, Reza Malekpour;Mollaei, Hamid Reza;Zandi, Bahare;Iranpour, Maryam
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.11
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    • pp.4907-4911
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    • 2016
  • Glioblastoma multiforme (GBM) is the most aggressive of the gliomas, a collection of tumors arising from glia in the central nervous system. Possible associations between the human cytomegalovirus (HCMV) and the JC virus with GBM are now attracting interest. Our present aim was to investigate the prevalence of the two viruses in Iranian patients from Kerman's cities in the south of Iran. In addition, the expression rates of pp65, large T antigen and p53 proteins were assessed and their relation with GBM evaluated using reverse transcription real time PCR (rReal Time PCR). A total of 199 patients with GBM cancer were enrolled, with $mean{\pm}SD$ ages of $50.0{\pm}19.5$ and $50.7{\pm}19.6$ years for males and females, respectively. The P53 rate was dramatically low suggesting an aetiological role,. Large T antigen expression was found in JC positive samples, while the PP65 antigen was observed in patients positive for CMV and JC. HCMV products and JC virus with oncogenic potential may induce the development of various tumors including glioblastomas. The JC virus produces an early gene product, T-antigen, which has the ability to associate with and functionally inactivate well-studied tumor suppressor proteins including p53 and pRB.

Roles of Human Papillomaviruses and p16 in Oral Cancer

  • Sritippho, Thanun;Chotjumlong, Pareena;Iamaroon, Anak
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.15
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    • pp.6193-6200
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    • 2015
  • Head and neck cancer, including oral cancer, is the sixth most common cancer in humans worldwide. More than 90% of oral cancers are of squamous cell carcinoma type. Recent studies have shown a strong relationship between human papillomavirus (HPV) infection and head and neck cancer, especially oropharyngeal squamous cell carcinoma (OPSCC) and oral squamous cell carcinoma (OSCC). Moreover, the incidence of HPV-related OSCC appears to be on the rise while HPV-unrelated OSCC tends to have stabilized in the past decades. p16, a tumor suppressor gene, normally functions as a regulator of the cell cycle. Upon infection with high-risk types of HPV (HR-HPV), particularly types 16, 18, 31, 33, 34, 35, 39, 51, 52, 56, 58, 59, 66, 68, and 70, the expression of p16 is aberrantly overexpressed. Therefore, the expression of p16 is widely used as a surrogate marker for HPV infection in head and neck cancer.

Epigenetic Regulation of miR-129-2 Leads to Overexpression of PDGFRa and FoxP1 in Glioma Cells

  • Tian, Xiang-Yang;Zhang, Ling;Sun, Lai-Guang;Li, Ming
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.14
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    • pp.6129-6133
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    • 2015
  • miR-129-2 is frequently downregulated in multiple cancers. However, how it is silenced in cancers remains unclear. Here we investigated the expression profile and potential biological function of miR-129-2 in glioblastoma (GBM), the most common and lethal form of brain tumors in adults. We showed that miR-129-2 is lost in GBM patient specimens and cultured cell lines. miR-129-2 expression could be restored upon treatment with a histone deadetylase inhibitor (trichostatin A) but not a DNA methylation inhibitor (5-Aza-2'-deoxycytidine), and more profound effect was observed with the treatment of these two drugs in combination. Furthermore, forced expression of miR-129-2 repressed the expression of major oncogenic genes such as PDGFRa and Foxp1 in GBMs. Consistently, expression of miR-129-2 significantly inhibits GBM cell proliferation in vitro. These results reveal that miR-129-2 is epigenetically regulated and functions as a tumor suppressor gene in GBMs, suggesting it may serve as a potential therapeutic target for GBM treatment.

MicroRNA-328 Inhibits Proliferation of Human Melanoma Cells by Targeting TGFB2

  • Li, Jing-Rong;Wang, Jian-Qin;Gong, Qing;Fang, Rui-Hua;Guo, Yun-Long
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.4
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    • pp.1575-1579
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    • 2015
  • Some microRNAs (miRNAs) have been shown to act as oncogenes or tumor suppressor genes in human melanomas. miR-328 is upregulated in blood cells of melanoma patients compared to in healthy controls. This suggests a role for miR-328 in melanoma that warrants investigation. In this study, we demonstrated miR-328 levels to be dramatically decreased in human melanoma cell lines. Moreover, forced expression of miR-328 inhibited proliferation and induced G1-phase arrest of the SK-MEL-1 melanoma cell line. We identified TGFB2 as a direct target gene for miR-328 using a fluorescent reporter assay and western blotting. Levels of TGFB2 were dramatically increased in human melanoma cell lines and were inversely correlated with the miR-328 expression level. Our findings provide new insights into the mechanisms of human melanoma development, indicating that miR-328 has therapeutic potential for this disease.