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We studied the localization of myosin-activating protein kinases in cardiomyocytes obtained from fetal human heart at 8-9 weeks gestation. It was found that at this developmental stage, smooth muscle/nonmuscle myosin light chain kinase (MLCK, 108 kDa) and its high-molecular weight isoform (MLCK, 210 kDa), skeletal MLCK and death-associated protein kinase (DAPK) are co-localized with nonmuscle myosin IIB in the premyofibrils. The data obtained suggest that cardiac nonmuscle myosin at 8-9 weeks gestation may serve as the substrate of the studied myosin-activating protein kinases that are likely to cooperatively regulate the formation of myofibrils. We revealed high-molecular weight isoform of smooth muscle/nonmuscle kinase MLCK-210 in developing human heart and determined the ratios of MLCK-108 and MLCK-210 at different gestational stages. In this case, the approximate time period of changes in these isoforms ratio was revealed (between 8-9 and 13 weeks), that can be associated with functional changes in the developing myocardium.

Lung cancer is one of the most frequent neoplasia in the Russia, the United States and Europe. This cancer is associated with functional activity changes of many genes. In the present study TIMP3, DAPK1 and AKR1B10 genes transcription analysis of squamous cell lung cancer specimens was carried out using reverse transcription-PCR. Substantial increasing of AKR1B10 transcription level is revealed in 80% tumor samples. TIMP3 and DAPK1 transcription level is considerably decreased in 76 and 72% tumor specimens, accordingly. These results may point out that all three genes are important for squamous cell lung cancer tumorogenesis while AKR1B10 is potential oncogene whereas TIMP3 and DAPK1 are potential tumor suppressor genes. We suggest that revealed substantial transcription level-changes of investigated genes may be used for oncodiagnostics.

Hamster tumor cell lines obtained with the Rous sarcoma virus and characterized by a high metastatic activity in vitro were transfected with the gene for C2+/calmodulin-dependent serine-threonine death-associated protein kinase (DAPk). Expression of DAPk in tumor cells dramatically reduced their survival in the blood of syngenic animals and their ability to produce metastases, but did not affect their tumorigenicity or the primary tumor growth. The DAPk-induced change in the metastatic phenotype was not accompanied by substantial changes in production and phosphorylation of v-Src or focal adhesion proteins (focal adhesion kinase and paxilline). The resulting system of transfected cells with a modulated metastatic potential provide a convenient model to study the molecular mechanisms of tumor progression at various steps.