Prenatal diagnosis and genetic analysis of a fetus with Miller-Dieker syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a fetus with lissencephaly.@*METHODS@#Genomic DNA was extracted from amniotic fluid sample and subjected to copy number variation (CNV) analysis.@*RESULTS@#The fetus was found to harbor a heterozygous 5.2 Mb deletion at 17p13.3p13.2, which encompassed the whole critical region of Miller-Dieker syndrome (MDS) (chr17: 1-2 588 909).@*CONCLUSION@#The fetus was diagnosed with MDS. Deletion of the PAFAH1B1 gene may account for the lissencephaly found in the fetus.

Prevalence of oral cancer self-examination among elderly people treated under Brazil's Unified Health System: household health survey / Prevalência de autoexame bucal é maior entre idosos assistidos no Sistema Único de Saúde: inquérito domiciliar

The aim of this study was to examine the prevalence of oral cancer self-examinationamong the elderly and confirm whether prevalence was higher among users of the dental services provided by Brazil's Unified Health System (SUS, acronym in Portuguese). A transversal study of elderly people aged between 65 and 74 years living in a large-sized Brazilian municipality was conducted using simple random sampling. Logistic regression was conducted and results were corrected for sample design and unequal weighting using the SPSS(r) software. The study assessed 740 individuals. A total of 492 met the inclusion criteria, of which 101 (22.4%) reported having performed an oral cancer self-examination. Prevalence was higher among users of the dental services provided by the SUS, higher-income individuals, people with higher levels of education, individuals that used a removable dental prosthesis, and people who had not experienced discomfort attributed to oral condition, and lower among people who sought regular and periodic dental treatment and individuals who did not have a drinking habit. This type of self-care should be encouraged by public health policies which respond to the needs of the elderly, with emphasis on users of private and philanthropic services, and other services outside the public health network.

Este estudo objetivou identificar a prevalência do autoexame bucal entre idosos e constatar se essa prevalência foi maior entre usuários de serviços odontológicos prestados pelo Sistema Único de Saúde (SUS). Estudo transversal conduzido a partir de amostragem probabilística complexa por conglomerados, entre idosos (65-74 anos) de um município brasileiro de grande porte populacional. Foi realizada regressão logística binária, as estimativas foram corrigidas pelo efeito de desenho e por ponderações, utilizando-se o SPSS(r). Dentre os 740 avaliados, atenderam aos critérios de inclusão 492 idosos e, destes, 101 (22,4%) relataram a prática do autoexame bucal. Esta prática foi maior entre idosos usuários dos serviços odontológicos prestados no SUS, entre aqueles com maior renda per capita, os com maior escolaridade, aqueles que utilizavam prótese dentária removível e entre os que não tiveram impactos decorrentes das desordens bucais; foi menor entre os que usaram serviços odontológicos por rotina e os que não possuíam hábito etilista. A prevalência do autoexame bucal entre idosos foi baixa e maior entre aqueles usuários do SUS. O estímulo à adesão a este autocuidado deve ser considerado nas políticas de saúde do idoso vigentes, especialmente entre usuários de serviços particulares, supletivos e filantrópicos.

Propuesta de reformas a los prestadores públicos de servicios médicos en Chile: “fortaleciendo la opción pública” / A reform proposal to strengthen public health care

Currently, there is no discussion on the need to improve and strengthen the institutional health care modality of FONASA (MAI), the health care system used by the public services net and by most of the population, despite the widely known and long lasting problems such as waiting lists, hospital debt with suppliers, lack of specialists and increasing services purchase transference to the private sector, etc. In a dichotomous sectorial context, such as the one of health’s social security in Chile (the state on one side and the market on the other), points of view are polarized and stances tend to seek refuge within themselves. As a consequence, to protect the public solution is commonly associated with protecting the “status quo”, creating an environment that is reluctant to change. The author proposes a solution based on three basic core ideas, which, if proven effective, can strengthen each other if combined properly. These are: network financing management, governance of health care services in MAI and investments and human resources in networked self-managed institutions. The proposal of these core ideas was done introducing a reality testing that minimizes the politic complexity of their implementation.

Apoptosis signal-regulating kinase 1 (ASK1) is linked to neural stem cell differentiation after ischemic brain injury

Neural stem cells (NSCs) have been suggested as a groundbreaking solution for stroke patients because they have the potential for self-renewal and differentiation into neurons. The differentiation of NSCs into neurons is integral for increasing the therapeutic efficiency of NSCs during inflammation. Apoptosis signal-regulating kinase 1 (ASK1) is preferentially activated by oxidative stress and inflammation, which is the fundamental pathology of brain damage in stroke. ASK1 may be involved in the early inflammation response after stroke and may be related to the differentiation of NSCs because of the relationship between ASK1 and the p38 mitogen-activated protein kinase pathway. Therefore, we investigated whether ASK1 is linked to the differentiation of NSCs under the context of inflammation. On the basis of the results of a microarray analysis, we performed the following experiments: western blot analysis to confirm ASK1, DCX, MAP2, phospho-p38 expression; fluorescence-activated cell sorting assay to estimate cell death; and immunocytochemistry to visualize and confirm the differentiation of cells in brain tissue. Neurosphere size and cell survival were highly maintained in ASK1-suppressed, lipopolysaccharide (LPS)-treated brains compared with only LPS-treated brains. The number of positive cells for MAP2, a neuronal marker, was lower in the ASK1-suppressed group than in the control group. According to our microarray data, phospho-p38 expression was inversely linked to ASK1 suppression, and our immunohistochemistry data showed that slight upregulation of ASK1 by LPS promoted the differentiation of endogenous, neuronal stem cells into neurons, but highly increased ASK1 levels after cerebral ischemic damage led to high levels of cell death. We conclude that ASK1 is regulated in response to the early inflammation phase and regulates the differentiation of NSCs after inflammatory-inducing events, such as ischemic stroke.

Molecules and their functions in autophagy

Autophagy is a self-degradation system of cellular components through an autophagosomal-lysosomal pathway. Over the last 15 yr, yeast genetic screens led to the identification of a number of genes involved in the autophagic pathway. Most of these autophagy genes are present in higher eukaryotes and regulate autophagy process for cell survival and homeostasis. Significant progress has recently been made to better understand the molecular mechanisms of the autophagy machinery. Especially, autophagy process, including the regulation of autophagy induction through mTOR and the nucleation and elongation in autophagosome formation through class III phosphatidylinositol 3-kinase complex and ubiquitin-like conjugation systems, became evident. While many unanswered questions remain to be answered, here, we summarize the recent process of autophagy with emphasis on molecules and their protein complexes along with advanced molecular mechanisms that regulate the autophagy machinery.

Induction of unfolded protein response during neuronal induction of rat bone marrow stromal cells and mouse embryonic stem cells

When we treated rat bone marrow stromal cells (rBMSCs) with neuronal differentiation induction media, typical unfolded protein response (UPR) was observed. BIP/GRP78 protein expression was time-dependently increased, and three branches of UPR were all activated. ATF6 increased the transcription of XBP1 which was successfully spliced by IRE1. PERK was phosphorylated and it was followed by eIF2alpha phosphorylation. Transcription of two downstream targets of eIF2alpha, ATF4 and CHOP/GADD153, were transiently up-regulated with the peak level at 24 h. Immunocytochemical study showed clear coexpression of BIP and ATF4 with NeuN and Map2, respectively. UPR was also observed during the neuronal differentiation of mouse embryonic stem (mES) cells. Finally, chemical endoplasmic reticulum (ER) stress inducers, thapsigargin, tunicamycin, and brefeldin A, dose-dependently increased both mRNA and protein expressions of NF-L, and, its expression was specific to BIP-positive rBMSCs. Our results showing the induction of UPR during neuronal differentiations of rBMSCs and mES cells as well as NF-L expression by ER stress inducers strongly suggest the potential role of UPR in neuronal differentiation.

Tunicamycin enhances TRAIL-induced apoptosis by inhibition of cyclin D1 and the subsequent downregulation of survivin

TNF-related apoptosis-inducing ligand (TRAIL) has been proposed as a promising cancer therapy that preferentially induces apoptosis in cancer cells, but not most normal tissues. However, many cancers are resistant to TRAIL by mechanisms that are poorly understood. In this study, we showed that tunicamycin, a naturally occurring antibiotic, was a potent enhancer of TRAIL-induced apoptosis through downregulation of survivin. The tunicamycin-mediated sensitization to TRAIL was efficiently reduced by forced expression of survivin, suggesting that the sensitization was mediated at least in part through inhibition of survivin expression. Tunicamycin also repressed expression of cyclin D1, a cell cycle regulator commonly overexpressed in thyroid carcinoma. Furthermore, silencing cyclin D1 by RNA interference reduced survivin expression and sensitized thyroid cancer cells to TRAIL; in contrast, forced expression of cyclin D1 attenuated tunicamycin-potentiated TRAIL-induced apoptosis via over-riding downregulation of survivin. Collectively, our results demonstrated that tunicamycin promoted TRAIL-induced apoptosis, at least in part, by inhibiting the expression of cyclin D1 and subsequent survivin. Of note, tunicamycin did not sensitize the differentiated thyroid epithelial cells to TRAIL-induced apoptosis. Thus, combined treatment with tunicamycin and TRAIL may offer an attractive strategy for safely treating resistant thyroid cancers.

Tunicamycin enhances TRAIL-induced apoptosis by inhibition of cyclin D1 and the subsequent downregulation of survivin

TNF-related apoptosis-inducing ligand (TRAIL) has been proposed as a promising cancer therapy that preferentially induces apoptosis in cancer cells, but not most normal tissues. However, many cancers are resistant to TRAIL by mechanisms that are poorly understood. In this study, we showed that tunicamycin, a naturally occurring antibiotic, was a potent enhancer of TRAIL-induced apoptosis through downregulation of survivin. The tunicamycin-mediated sensitization to TRAIL was efficiently reduced by forced expression of survivin, suggesting that the sensitization was mediated at least in part through inhibition of survivin expression. Tunicamycin also repressed expression of cyclin D1, a cell cycle regulator commonly overexpressed in thyroid carcinoma. Furthermore, silencing cyclin D1 by RNA interference reduced survivin expression and sensitized thyroid cancer cells to TRAIL; in contrast, forced expression of cyclin D1 attenuated tunicamycin-potentiated TRAIL-induced apoptosis via over-riding downregulation of survivin. Collectively, our results demonstrated that tunicamycin promoted TRAIL-induced apoptosis, at least in part, by inhibiting the expression of cyclin D1 and subsequent survivin. Of note, tunicamycin did not sensitize the differentiated thyroid epithelial cells to TRAIL-induced apoptosis. Thus, combined treatment with tunicamycin and TRAIL may offer an attractive strategy for safely treating resistant thyroid cancers.

Familial cerebral cavernous malformations: Rio de Janeiro study and review of the recommendations for management / Malformação cavernosa cerebral familiar: um estudo no Rio de Janeiro e revisão das recomendações para tratamento

OBJECTIVE: Multiple cerebral cavernous malformation (CCM) is the hallmark of familial presentation of cavernous malformation in the brain. We describe an ongoing Familial Cerebral Cavernous Malformation Project in the Rio de Janeiro state showing genetic profile and the pattern of emergent neuroimaging findings of this particular population besides a review of the updated recommendations for management of familial CCM versus patients harboring sporadic lesions. METHOD: Four families of our cohort of 9 families were genetically mapped showing mutational profile linked to CCM1. The neuroimaging paradigm was shifted from T2*gradient-echo (GRE) sequence to susceptibility weighting MR phase imaging (SWI). RESULTS: Only two index cases were subjected to surgery. There was no surgical intervention in any of the kindreds of our entire cohort of 9 families of our Neurovascular Program within seven years of follow-up. The genetic sequencing for mutacional profile in four of these families has demonstrated only CCM1 gene affected. Our management of the familial CCM is according to the review of the literature recommendations. CONCLUSIONS: The Project of Familial Cerebral Cavernous Malformations of Rio de Janeiro detected mutations of the gene CCM1 in the first four families studied. Familial cavernous malformation are to be settled apart from the more common sporadic lesion. A set of recommendations was searched for in the literature in order to deal with these specific patients and kindreds.

OBJETIVOS: A apresentação de malformação cavernosa cerebral (CCM) através de múltiplas lesões cerebrais é a marca da forma familiar da doença. Os autores descrevem o Projeto Malformação Cavernosa Cerebral Familiar, em andamento no Rio de Janeiro, demonstrando o perfil genético e o padrão atual de achados neurorradiológicos dessa população específica e uma revisão das recomendações atuais para o manuseio e tratamento dos portadores dessa forma da doença versus os pacientes com malformação cavernosa cerebral esporádica. MÉTODO: Quatro familias de nossa coorte de 9 familias foram completamente mapeadas geneticamente e demonstraram padrão mutacional sempre ligado ao gene CCM1. O paradigma de neurimagens dessa população foi mudado para a seqüência de susceptibility weighting MR phase imaging (SWI) em substituição à seqüência T2*gradient-echo (GRE). RESULTADOS: Apenas 2 casos indices foram submetidos à ressecção cirúrgica. Não houve intervenção cirúrgica em nenhum outro parente de toda a coorte de 9 familias no período de sete anos de acompanhamento. O sequenciamento genético em busca do perfil mutacional foi completado em 4 familias demonstrando o acometimento do gene CCM1 em todas. O manuseio e tratamento de nossa população de malformação cavernosa cerebral familiar está de acordo com a revisão feita sobre recomendações da literatura. CONCLUSÃO: O Projeto Malformação Cavernosa Cerebral Familiar detectou mutações do gene CCM1 nas primeiras quatro famílias estudadas. Os portadores dessa forma de malformação cavernosa cerebral da doença devem ser considerados à parte na rotina de avaliação e tratamento em relação à forma esporádica da doença. As recomendações foram buscadas na literature para nortear o manuseio dessa população específica.

[Evaluating the expression of survivin and its splice variants; 2B and AEx3 as new diagnostic molecular markers in thyroid cancer]

Thyroid cancer is the most common endocrine malignancy. Because of the highly heterogeneous nature of tumoral and non-tumoral thyroid nodules and lack of suitable clinico-pathological criteria and absence of appropriate molecular markers, scientists have been trying to find a molecular tumor marker for specific diagnosis of thyroid tumors. Recent attention has been paid to Survivin, a novel member of the Inhibitor of Apoptosis Protein Family [IAP], as a new molecular marker in cancer. Studies have demonstrated that Survivin and its splice variants have different expression in cancerous tissues compared to normal tissues. In this study the expression of Survivin and its splice variants; 2B and [delta] Ex3 were evaluated as new diagnostic molecular markers in thyroid cancer. Tissue samples were collected from 61 thyroid specimens including 14 tumor margins, 11 non-tumoral and 36 tumoral samples. Expression levels of Surviving and its variants were measured by semi quntitative RT-PCR. Expression level of Survivin in tumor samples was significantly higher compared with surgical margins and non tumural tissues. There was also a significant increase in expression level of Survivin-[delta]Ex3 in tumoral tissues compared with surgical margins. The expression of Survivin 2B in tumors was lower than the non-tumoral tissues. Our data indicated the important role of Survivin in production of thyroid tumors and also revealed that high expression of [delta]Ex3 variant is correlated with nature of thyroid tumors. Therefore, evaluating Survivin gene expression and its recently introduced splice variants may be used in diagnosis and classification of thyroid tumors from non-tumoral lesions

Expression and prognostic significance of survivin in the progression of bladder transitional cell cancer / 华中科技大学学报（医学）（英德文版）

The expression of survivin, a member of inhibitor of apoptosis (IAP) family, was examined in bladder transitional cell cancer (BTCC) tissue and adjacent normal tissues to examine its clinical implication in the development of BTCC. Thirty specimens of bladder cancer were detected for the expression of survivin by using immunohistochemistry and real-time quantitative reverse transcription polymerase chain reaction (RT-QPCR) in BTCC tissue and adjacent normal tissues. Our results showed that the positive rate of survivin immunostaining specimen were 0 and 60% (18/30) in the adjacent normal tissues, bladder cancer, respectively. The-DeltaDeltaCT value of survivin in bladder cancer tissue was 10.2829 (9.0034-11.5624) times that in the adjacent normal tissues. The expressions of survivin were correlated with the pathological grades of tumor and clinical stages. It is concluded that there was only weak expression of survivin mRNA in the adjacent normal tissues, but the expression of survivin mRNA in bladder cancer tissue was much higher than that in the adjacent normal tissues and the expression of survivin was correlated with pathological grades and clinical stages of tumor.

Knockdown of survivin expression by siRNA induces apoptosis of hepatocellular carcinoma cells / 华中科技大学学报（医学）（英德文版）

Survivin, a newly identified member of IAP family, is a powerful apoptosis-inhibiting factor. It is expressed in embryonic tissues as well as in the majority of human cancers, but not in most normal adult tissues. The cancer-specific expression of survivin makes it a potential target for cancer treatment. A survivin-specific small inhibitory RNA (siRNA) was introduced into hepatocellular carcinoma cells to investigate its effect on cancer cell apoptosis, growth and sensitivity to chemotherapeutic drugs. It was found that expressions of survivin protein and proliferation index (PI) in siRNA groups were significantly decreased, the apoptosis index (AI) of siRNA groups was significantly higher than those of others groups, and the growth inhibition rate (GIR) of chemotherapeutic drugs in siRNA groups were significantly higher than those of other groups. Our study suggests that the expression of survivin may be significantly decreased in hepG2 cell after siRNA transfection. siRNA targeting survivin could induce cell apoptosis, inhibit cell proliferation and sensitize hepatocarcinoma cells to chemotherapy. Our findings provide preliminary evidence for the therapeutic use of survivin-targeted RNA interference for human tumors that express high levels of this molecule.

Expression of survivin and its splice variants in gastric cancer / 华中科技大学学报（医学）（英德文版）

Survivin variants specific real time quantitative RT-PCR was developed to analyze their expression in 53 paired cancer and para-cancerous tissues, and the expression of the wild-type survivin protein was detected by immunohistochemistry. The results showed that survivin mRNA and protein were expressed in gastric cancer and para-cancerous tissues. The survivin-2B was dominantly expressed in para-cancerous tissues, whereas the survivin-DeltaEx3 was more frequently detected in cancer tissues. The positive rate of survivin-2a was 100% in both cancer and para-cancerous tissues, but its relative transcript expression level was not significantly increased in cancer tissues in comparison with para-cancerous tissues. The correlation analysis revealed that the expression of survivin-2a mRNA was significantly associated with that of total survivin (r (s)=0.4178, P=0.0018), whereas inversely to that of survivin-DeltaEX3 (r (s)=-0.4506, P=0.0007). It was suggested that survivin-2a may act as an antagonist of survivin-DeltaEX3. The balance between antiapoptotic survivin iso-forms and nonantiapoptotic ones may play an important role in tumorigenesis and tumor progression. Promising value is hinted to analyze survivin and its variants in tumor early diagnosis and distinguishing malignant tumors from benign ones.

Neuronal Apoptosis Inhibitory Protein is Overexpressed in Patients with Unfavorable Prognostic Factors in Breast Cancer

Neuronal apoptosis inhibitory protein (NAIP) is a recently identified inhibitor of apoptosis protein. However, the clinical relevance of NAIP expression is not completely understood. In an attempt to determine the clinical relevance of NAIP expression in breast cancer, the levels of NAIP and survivin expression were measured in 117 breast cancer samples and 10 normal breast tissues using quantitative reversetranscriptase-polymerase chain reaction. While there was no evidence of NAIP expression in the normal breast tissue, NAIP was expressed in all breast cancer samples. The level of NAIP expression in breast cancer was significantly higher (257 times) than in the universal tumor control. There was a strong correlation between the level of NAIP expression and the level of survivin expression (p=0.001). The level of NAIP expression in patients with a large tumor (> or =T2) and patients with an unfavorable histology (nuclear grade III) was significantly higher than in those patients with a small tumor (T1) and patients with a favorable histology (nuclear grade I, II) (p=0.026 and p=0.050, respectively). Although the level of NAIP expression was higher in patients with other unfavorable prognostic factors, it was not significant. The three-year relapse-free survival rate was not significantly the patients showing high NAIP expression and patients showing low NAIP expression (86.47+/-4.79% vs. 78.74+/-6.57%). Further studies should include the expressions of NAIP in a larger number of patients and for a longer period of follow-up to evaluate correlation with metastasis and treatment outcome. In conclusion, NAIP is overexpressed in breast cancer patients with unfavorable clinical features such as stage and tumor size, suggesting that NAIP would play a role in the disease manifestation.

Antisurvivin oligonucleotides inhibit growth and induce apoptosis in human medullary thyroid carcinoma cells

Suvivin is a novel member of the inhibitor of apoptosis protein (IAP) family, which is known to be over-expressed in various carcinomas and associated with their biologically aggressive characteristics. The aim of this study was to investigate survivin expression in human medullary thyroid carcinoma (MTC) and a MTC cell line TT, correlate suvivin expression with clinicopathologic features of MTC, and test effects of antisurvivin oligonucleotides (ASODNs) on growth and apoptosis of TT cells. Survivin expression was immunohistochemically determined in formalin-fixed and paraffin-embedded specimens obtained from 10 cases of normal thyroid (NT) and 10 cases of MTC, and in TT cells. In TT cells, we confirmed survivin expression and its down-regulation by ASODNs using RT-PCR and Western blot analyses, and investigated effects of ASODNs on viability and growth by MTT assay and apoptosis by apoptotic analyses including DNA laddering assay, acridine orange/ethidium bromide staining and flow cytometric cell cycle analysis. Immunohistochemical analysis showed high survivin expression in MTC and TT cells, whereas no immunoreactivity was detectable in NT. Statistical analyses revealed no significant correlation of survivin expression with the clinicopathologic features of MTC. In TT cells, survivin expression at both mRNA and protein levels was confirmed and could be down-regulated by ASODNs concomitant with decrease in viability and growth, and increase in apoptosis. Our results suggest that survivin plays an important role in MTC independent of the conventional clinicopathologic factors, and ASODNs is a promising survivin-targeted gene therapy for MTC.

A Novel Missense Mutation of Doublecortin: Mutation Analysis of Korean Patients with Subcortical Band Heterotopia

The neuronal migration disorders, X-linked lissencephaly syndrome (XLIS) and subcortical band heterotopia (SBH), also called "double cortex", have been linked to missense, nonsense, aberrant splicing, deletion, and insertion mutations in doublecortin (DCX) in families and sporadic cases. Most DCX mutations identified to date are located in two evolutionarily conserved domains. We performed mutation analysis of DCX in two Korean patients with SBH. The SBH patients had mild to moderate developmental delays, drug-resistant generalized seizures, and diffuse thick SBH upon brain MRI. Sequence analysis of the DCX coding region in Patient 1 revealed a c.386 C>T change in exon 3. The sequence variation results in a serine to leucine amino acid change at position 129 (S129L), which has not been found in other family members of Patient 1 or in a large panel of 120 control X-chromosomes. We report here a novel c.386 C>T mutation of DCX that is responsible for SBH.

Isolated lissencephaly sequence with contiguous gene deletion detected by FISH analysis: a case report.

BACKGROUND: Lissencephaly is a clinically and genetically heterogeneous malformation of the brain, usually leading to a severe disabling condition and seizures. The recent discovery of molecular techniques and identification of lissencephaly genes (e.g. LISI and DCX) has allowed etiologic diagnosis of this disorder feasible. OBJECTIVE: To describe a patient with lissencephaly in whom fluorescence in situ hybridization (FISH) determined etiologic diagnosis, providing precise genetic counseling and possible prenatal diagnosis for the family. CLINICAL REPORT AND STUDY RESULTS: The authors report a 4 month-old girl who presented with intractable, generalized myoclonic seizures at I month of age. The patient was born at 37 weeks' gestation, to a G4P1A2 36-year-old woman. Chromosome analysis from amniotic fluid performed for advanced maternal age revealed normal karyotype. Pregnancy was complicated by polyhydramnios. Computed tomographic scan of the brain at age one month showed a total absence of gyral formation. FISH of the metaphase chromosome from the patient, using Smith-Magenis and Miller-Dieker/ILS probe showed two signals of Smith-Magenis probe but only one signal of Miller-Dieker/ILS probe, indicating a microdeletion of 17pl3.3 region including LIS1 gene. Hybridization of the ILS probe on the metaphase chromosome of both parents was normal. CONCLUSION: A confirmation of contiguous gene deletion in this patient lead to an etiologic diagnosis of lissencephaly. This information allowed precise genetic counseling, estimation of recurrent risk, and definite prenatal diagnosis available to the family. The authors suggest FISH 17p13.3 studies be performed in addition to a standard metaphase analysis in all patients with type I lissencephaly.

Mutation and expression of the p27KIP1 and p57KIP2 genes in human gastric cancer

Cyclin-dependent kinase inhibitors (CDKI) are negative regulators of cell cycle progression by binding the cyclin-CDK complex and inhibiting the CDK activity. Genetic alteration in the CDKI genes has been implicated for carcinogenesis. To test the genetic alteration in the p27 and p57 genes, KIP family CDKI genes, 30 gastric tumor-normal pairs and 8 gastric cancer cell lines were analyzed for mutations by polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP). No mutation was detected in these genes although length polymorphisms in the proline-alanine repeat of the p57 gene were detected. When the p27 and p57 mRNAs were analyzed in gastric cancer cell lines by RT-PCR, the p27 mRNA was expressed considerably high in tumor cells but expression of the p57 mRNA was much low in gastric cancer cell lines compared to that of normal cells. The result suggests that inactivation of gene expression rather than mutations in the p57 gene accounts possibly for the involvement of this gene in tumorigenesis of gastric cancer. However, expression of the p27 gene seems to be essential for cell survival.