• Title/Summary/Keyword: K-ras mutation

Search Result 45, Processing Time 0.021 seconds

Phosphorylation of SAV1 by mammalian ste20-like kinase promotes cell death

  • Park, Byoung-Hee;Lee, Yong-Hee
    • BMB Reports
    • /
    • v.44 no.9
    • /
    • pp.584-589
    • /
    • 2011
  • The mammalian ste20-like kinase (MST) pathway is important in the regulation of apoptosis and cell cycle and emerges as a novel tumor suppressor pathway. MST-induced phosphorylation of Salvador homolog 1 (SAV1), which is a scaffold protein, has not been evaluated in detail. We performed a mass spectrometric analysis of the SAV1 protein that was co-expressed with MST2. Phosphorylation was detected at Thr-26, Ser-27, Ser-36 and Ser-269. Although single or double mutations had little effects, the mutation of all four residues in SAV1 to Ala (SAV1-4A) had inhibitory effects on the MST pathway. MST2-mediated induction of SAV1-4A protein levels, SAV1-4A interaction with MST2 and the self-dimerization of SAV1-4A were weaker compared to those of wild-type SAV1. SAV1-4A inhibited MST2- and K-RasG12V-induced cell death of MCF7 cells. These results suggest that MST-mediated phosphorylation of four residues within SAV1 may be important in the induction of cell death by the MST pathway.

Noonan syndrome and RASopathies: Clinical features, diagnosis and management

  • Lee, Beom Hee;Yoo, Han-Wook
    • Journal of Genetic Medicine
    • /
    • v.16 no.1
    • /
    • pp.1-9
    • /
    • 2019
  • Noonan syndrome (NS) and NS-related disorders (cardio-facio-cutaneous syndrome, Costello syndrome, NS with multiple lentigines, or LEOPARD [lentigines, ECG conduction abnormalities, ocular hypertelorism, pulmonic stenosis, abnormal genitalia, retardation of growth and sensory neural deafness] syndrome) are collectively named as RASopathies. Clinical presentations are similar, featured with typical facial features, short stature, intellectual disability, ectodermal abnormalities, congenital heart diseases, chest & skeletal deformity and delayed puberty. During past decades, molecular etiologies of RASopathies have been growingly discovered. The functional perturbations of the RAS-mitogen-activated protein kinase pathway are resulted from the mutation of more than 20 genes (PTPN11, SOS1, RAF1, SHOC2, BRAF, KRAS, NRAS, HRAS, MEK1, MEK2, CBL, SOS2, RIT, RRAS, RASA2, SPRY1, LZTR1, MAP3K8, MYST4, A2ML1, RRAS2). The PTPN11 (40-50%), SOS1 (10-20%), RAF1 (3-17%), and RIT1 (5-9%) mutations are common in NS patients. In this review, the constellation of overlapping clinical features of RASopathies will be described based on genotype as well as their differential diagnostic points and management.

Sex-related Clinicopathologic Differences in Patients with Adenocarcinoma of the Lung (성별에 따른 원발성 폐선암 환자들의 차이)

  • Park, Eun Ho;Jang, Tae Won;Jang, Li La;Paek, Jong yun;Oak, Chul Ho;Jung, Mann Hong;Jang, Hee Kyung
    • Tuberculosis and Respiratory Diseases
    • /
    • v.62 no.3
    • /
    • pp.203-210
    • /
    • 2007
  • Background: The incidence of adenocarcinoma of the lung has been increasing worldwide, and it has been generally been accepted to be relatively unrelated to smoking with a female preponderance. The aim of this study was to examine the gender-related pathological and survival differences in patients with an adenocarcinoma of the lung. Material and Method: A retrospective review of the clinical information of patients diagnosed with an adenocarcinoma of the lung at Kosin Medical Center from January 1999 to September 2005 was performed. The patient's demographics (age, gender), smoking history, stage, serum tumor marker, pathology classification, EGFR mutation, K-ras mutation, treatment methods, and survival time were analyzed. Result: Of the 438 patients, 179 (40.9%) were female. The median age at the diagnosis was 58 years for females and 59 years for males. However, 25.8% of women and only 17.7% of men were under 50 years of age (p=0.02). The distribution of the disease stage was similar in both men and women. The bronchioloalveolar carcinoma component was diagnosed more often in women (11.2%) than in men (5.0%). The overall survival rate was higher in women than in men (p=0.01), and women had a superior therapeutic response to a combined treatment of surgery and chemotherapy. Conclusion: This study showed significant genders differences in terms of the smoking history, bronchioloalveolar carcinoma component, overall survival, and survival after combined treatment of surgery and chemotherapy. Therefore, gender differences should be considered when diagnosing and treating adenocarcinomas of the lung.

MGMT-B Gene Promoter Hypermethylation in Patients with Inflammatory Bowel Disease - A Novel Finding

  • Mokarram, Pooneh;Kavousipour, Soudabeh;Sarabi, Mostafa Moradi;Mehrabani, Golnosh;Fahmidehkar, Mohammad Ali;Shamsdin, Seyedeh Azra;Alipour, Abbas;Naini, Mahvash Alizade
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.16 no.5
    • /
    • pp.1945-1952
    • /
    • 2015
  • Inflammatory bowel disease (IBD) is a disease strongly associated with colorectal cancer (CRC) as a well-known precancerous condition. Alterations in DNA methylation and mutation in K-ras are believed to play an early etiopathogenic role in CRC and may also an initiating event through deregulation of molecular signaling. Epigenetic silencing of APC and SFRP2 in the WNT signaling pathway may also be involved in IBD-CRC. The role of aberrant DNA methylation in precancerous state of colorectal cancer (CRC) is under intensive investigation worldwide. The aim of this study was to investigate the status of promoter methylation of MGMT-B, APC1A and SFRP2 genes, in inflamed and normal colon tissues of patients with IBD compared with control normal tissues. A total of 52 IBD tissues as well as corresponding normal tissues and 30 samples from healthy participants were obtained. We determined promoter methylation status of MGMT-B, SFRP2 and APC1A genes by chemical treatment with sodium bisulfite and subsequent MSP. The most frequently methylated locus was MGMT-B (71%; 34 of 48), followed by SFRP2 (66.6 %; 32 of 48), and APC1A (43.7%; 21 of 48). Our study demonstrated for the first time that hypermethylation of the MGMT-B and the SFRP2 gene promoter regions might be involved in IBD development. Methylation of MGMT-B and SFRP2 in IBD patients may provide a method for early detection of IBD-associated neoplasia.

STUDY ON mRNA EXPRESSION OF P21 AND P73 IN THE CELL LINES OF PRIMARY AND METASTATIC SQUAMOUS CELL CARCINOMA (원발성 및 전이성 구강편평세포암종 세포주에서 p21 및 p73 mRNA발현에 관한 연구)

  • Kang, Jeong-Hoon;Kim, Kyung-Wook;Lee, Jae-Hoon
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • v.27 no.6
    • /
    • pp.483-490
    • /
    • 2001
  • There were many controversies in the cause and progress of tumorigenesis. Recently, studies on the mutation of genes related to the tumor have extensively been performed due to development of molecular biology. Structural and morphological changes of chromosomes, which are related to the abnormal activation of oncogenes or inactivation of tumor suppression genes, transform the normal cells into the tumor cells. p53 and Rb are well known tumor suppressor genes, while oncogenes include c-myc, bcl-2 and ras, etc. When exposed to cell damaging agents, p53 inhibits cell growth by inducing transcription of p21. Especially p73, which is homo-logy of p53, frequently deleted in melanoma, neuroblastoma, colon cancer, and breast cancer, when over produced, p73 activates the transcription of p21, bax-1 and inhibits cell growth by inducing apoptosis. For study on mRNA expression of p21 and p73, normal oral keratinocytes, and cell lines of primary and metastatic oral squamous cell carcinoma were cultured and then electrophoresis and RT-PCR(reverse transcription-polymerase chain reaction) were performed. 1. The mRNA of p21 and p73 in normal oral keratinocyte expressed lower than that of primary squamous cell carcinoma. 2. The mRNA of p21 in metastatic oral squamous carcinoma cell lines was expressed as various patterns compared with that of normal oral keratinocyte. 3. In the metastatic oral squamous cell lines, the mRNA of HN8 expressed higher than that of HN12 or HN19. 4. The mRNA of p73 in primary oral squamous cell lines expressed 4-5 times higher than that of normal keratinocyte. 5. In metastatic oral squamous cell lines, there was no significant expression of p73 mRNA compared with that of normal oral keratinocyte. From the results obtained in this study, mRNA expression of p73 in primary oral squamous cell lines was remarkable, while mRNA expression of p21 and p73 in metastatic oral squamous cell lines were statistically insignificant.

  • PDF