Spectrum of APC and MUTYH germ-line mutations in Russian patients with colorectal malignancies.

Distribution of cancer-predisposing mutations demonstrates significant interethnic variations. This study aimed to evaluate patterns of APC and MUTYH germ-line mutations in Russian patients with colorectal malignancies. APC gene defects were identified in 26/38 (68%) subjects with colon polyposis; 8/26 (31%) APC mutations were associated with 2 known mutational hotspots (p.E1309Dfs*4 [n = 5] and p.Q1062fs* [n = 3]), while 6/26 (23%) mutations were novel (p.K73Nfs*6, p.S254Hfs*12, p.S1072Kfs*9, p.E1547Kfs*11, p.L1564X and p.C1263Wfs*22). Biallelic mutations in MUTYH gene were detected in 3/12 (25%) remaining subjects with polyposis and in 6/90 (6.7%) patients with colorectal cancer (CRC) carrying KRAS p.G12C substitution, but not in 231 early-onset CRC cases negative for KRAS p.G12C allele. In addition to known European founder alleles p.Y179C and p.G396D, this study revealed a recurrent character of MUTYH p.R245H germ-line mutation. Besides that, 3 novel pathogenic MUTYH alleles (p.L111P, p.R245S and p.Q293X) were found. Targeted next-generation sequencing of 7 APC/MUTYH mutation-negative DNA samples identified novel potentially pathogenic POLD1 variant (p.L460R) in 1 patient and known low-penetrant cancer-associated allele CHEK2 p.I157T in 3 patients. The analysis of 1120 healthy subjects revealed 15 heterozygous carriers of recurrent MUTYH mutations, thus the expected incidence of MUTYH-associated polyposis in Russia is likely to be 1:23 000.

PCR-based detection of EGFR, ALK, KRAS and BRAF mutations in Russian patients with lung adenocarcinoma: a single-center experience.

In contrast to other countries with predominantly white populations, Russian smoking-related lung cancers (LC) are mainly squamous cell carcinomas and approximately half lung adenocarcinomas (AdCa) are not related to tobacco consumption. Given that smoking significantly influences the probability of presence of actionable mutations in LC, one would expect that Russian lung AdCa patients would differ from other white populations in distribution of EGFR, ALK, KRAS and BRAF mutations. Herein, 2,336 consecutive lung AdCa cases, including 1,203 patients with known smoking status, were subjected to sequential testing for the above mutations. One quarter of lung AdCa patients carried either EGFR or ALK mutation with combined prevalence of 42% in those who had never smoked but only 8% in smokers. There was only a moderate difference in KRAS mutation frequency between ever- and never-smokers in EGFR/ALK-negative cases (31% vs. 23%), and this was mainly attributed to increased prevalence of G12C substitution in the former group. The occurrence of BRAF V600E mutation was 1.7% and 4% in EGFR/ALK/KRAS mutation-negative ever- and never-smokers, respectively. ALK testing of 470 EGFR-mutated tumors revealed only 1 (0.2%) instance of translocation. Similarly, KRAS testing identified 1 (1.25%) mutation in 80 EGFR-mutated AdCa and none in 48 ALK-rearranged AdCa. Therefore, concurrent actionable mutations in lung adenocarcinoma are exceptionally rare and sequential gene testing can be regarded as a reliable option.

[Pharmacoeconomic analysis of gefitinib therapy in patients with non-cell cell lung cancer].

We performed a treatment efficacy analysis for non-small cell lung cancer (NSCLC) patients' population with EGFR mutation aimed at optimization of pharmacoeconomic factors. The employment of gefitinib leads to an increase in patients' life expectancy for a median of 1.05 years. The average cost-effectiveness of this therapy is 934.8 thousand rubles per additional year (903.9-1100.5 thousand rubles for each year). If gefitinib therapy is given only to patients with proved EGFR mutation it can decrease the average expenses by 211.6-251.8 thousand rubles per patient in comparison to undiagnosed patients's population receiving gefitinib without a decrease in clinical effect. Comparison of selective gefitinib administration with isolated chemotherapy (CT) yields an incremental cost-effectiveness ratio of 960.7 to 1010.0 thousand rubles per additional year. Therefore, the strategy of EGFR gene mutations testing in patients with inoperable NSCLC with consequent gefitinib therapy administration in patients positive for mutation lead to an increase in life expectancy and is characterized by acceptable cost-effectiveness.

[Effectiveness of gefitinib (Iressa) as first-line therapy for inoperable non-small-cell lung cancer with mutated EGFR gene (phase II study)].

Tumor regression was reported in 20-30% of patients with inoperable non-small-cell lung cancer (NSLC) following standard first-line chemotherapy. Clinical trials with second-line gefitinib (Iressa) showed a strikingly high response in patients with mutated EGFR. However, clinical experience with gefitinib as first-line therapy had been limited to small-scale trials mostly among subjects of Asian origin. Our study was not associated with the drug manufacturer and included 25 chemotherapy-naive patients with mutated EGFR inoperable lung adenocarcinoma. Standard dose was 250 mg/day. Complete response was observed in 1 patient (4%), partial--11 (44%), sustained stabilization--13 (52%); median time until tumor progression--186 days. Median overall survival failed to be registered within the duration of the study. Among most frequent side-effects were skin rash (19; 76%) and diarrhea (14; 56%): marked side-effect -toxicity grade III (4; 16%). Gefitinib appeared highly efficient and tolerable and may be recommended as first-line treatment of mutated EGFR inoperable NSLC.

Distinct prevalence of the CYP19 Delta3(TTTA)(7) allele in premenopausal versus postmenopausal breast cancer patients, but not in control individuals.

The CYP19 gene encodes the enzyme aromatase, which plays a key role in the conversion of androgens to oestrogens. A polymorphism in CYP19 in intron 4 (TTTA)n has been reported to be associated with breast cancer (BC) risk, although conflicting evidence has also been published. Here, we employ a non-traditional, highly demonstrative design of a molecular epidemiological study, where the comparison of BC cases and healthy middle-aged female donors was supplemented by an analysis of groups with extreme characteristics of either BC risk (bilateral breast cancer (biBC) patients) or cancer tolerance (tumour-free elderly women aged >or=75 years). None of the (TTTA)n polymorphic variants was significantly overrepresented among the affected women compared with any of the control groups. However, a 3-bp deletion/insertion CYP19 polymorphism, which is located in the same intron approximately 50 bp upstream to the (TTTA)n repeat, was evidently associated with the menopausal status in both the BC and biBC cohorts. In particular, the Delta3(TTTA)(7) allele occurred significantly more frequently in premenopausal than in postmenopausal BC patients (65/172 (38%) versus 67/310 (22%); P=0.0001; Odds Ratio (OR)=2.20 (95% Confidence Interval (CI) 1.46-3.32)), while the perimenopausal cases demonstrated an intermediate value (9/34 (26%)). In the biBC cohort, women who developed both tumours during their premenopausal period had a significantly higher prevalence of the Delta3(TTTA)(7) allele than patients with a postmenopausal onset of bilateral disease (16/46 (35%) versus 8/50 (16%); P=0.035; OR=2.80 (1.08-7.23)); those biBC patients, whose tumours were diagnosed before and after the cessation of menses, displayed an intermediate occurrence of the Delta3(TTTA)(7) allele (7/32 (22%)). Similar tendencies in the Delta3(TTTA)(7) allele distribution in BC and biBC patients suggest that its association with the menopausal status of the patients is truly non-random and thus this observation deserves further detailed investigation.

Evidence for microsatellite instability in bilateral breast carcinomas.

The molecular pathogenesis of various categories of breast cancer (BC) has been well described, but surprisingly few reports have appeared on analysis of somatic mutations in bilateral BC. We have performed a polymerase chain reaction (PCR)-driven investigation of chromosomal regions showing common loss of heterozygosity (LOH) in 23 cases (46 tumors) from patients diagnosed with bilateral BC. LOH was observed in 15/46 (33%) informative tumors for chromosome 1p, 5/32 (16%) for 5q, 12/44 (27%) for 11q, 15/40 (38%) for 13q and 4/24 (17%) for 17p. These values are within the range of interlaboratory variations reported for unilateral BC. There was no strong evidence for concordance of LOH within the same patient for any of the chromosomal loci tested. Atypical for breast carcinomas, 7/46 (15%) tumors accumulated a high frequency (ranging from 11 to 29%) of shortened dinucleotide CA repeats, implying microsatellite instability (MI). Further analysis with the highly informative BAT-26 marker allowed for the classification of two of these tumors as having a replication error positive (RER(+)/MSI-H) phenotype, whereas the remaining five carcinomas harbored so-called borderline MI. Thus an involvement of both RER(+) and borderline MI appears to be a distinct feature of bilateral breast carcinomas compared to unilateral lesions.

CYP17 polymorphism in the groups of distinct breast cancer susceptibility: comparison of patients with the bilateral disease vs. monolateral breast cancer patients vs. middle-aged female controls vs. elderly tumor-free women.

The CYP17 gene encodes an enzyme involved in several critical steps of steroidogenesis. The promoter region of the CYP17 displays a single-nucleotide polymorphism, which is suspected to modulate the expression of the gene and thus may contribute in the interindividual variations of hormonal background. In agreement with this functional hypothesis, the MspA1+ allele (designated as A2) of the CYP17 was shown to render an increased risk of breast cancer (BC). However, the latter observation was disputed by a series of negative reports. Here, we re-evaluated the role of CYP17 MspA1 polymorphism in the BC susceptibility, using a non-traditional design of a case-control study. In addition to randomly selected 183 BC patients and 107 female middle-aged donors, we examined the groups with apparently extreme characteristics of either BC risk or BC resistance, namely the 57 bilateral breast cancer (biBC) patients and 75 elderly (>/=75 years old) tumor-free women. Neither BC nor biBC patients showed increased prevalence of 'unfavorable' A2 allele as compared with the non-affected cohorts. Moreover, the A2 variant was not significantly associated with the tumor size, nodal involvement and menopausal status in the patients either with the monolateral or bilateral disease. Thus, our data argue against the earlier reported role of the CYP17 in BC predisposition and progression. In addition, usual distribution of the CYP17 alleles in the elderly group indicates a neutral effect of this polymorphism on the longevity in females.

GSTM1 genotypes in elderly tumour-free smokers and non-smokers.

Cancer is known to be an extremely common disease, with the life-time risks reaching close to 0.5 for men and to 0.4 for women. Hence those individuals, who succeeded to achieve a reasonably old age without a history of malignancy, represent a distinct group of interest, which apparently can be defined as 'tumour-tolerant'. Focus on the genetic features of these subjects may significantly facilitate the research of cancer-predisposing polymorphisms: first, a fundamental understanding of molecular mechanisms conferring the phenomena of cancer resistance appears to be outstandingly important; second, it is promising to involve non-affected geriatric cohorts in the molecular epidemiological studies as a tumour-free control of especial value. Here we analysed the GSTM1 genotype frequencies in the individuals with seemingly different degrees of resistance or susceptibility to neoplasms, such as elderly tumour-free smokers and non-smokers (> or = 75-years-old), healthy middle-aged donors, and lung cancer patients. The proportion of GSTM1-deficient individuals gradually increased from elderly controls (70/157; 45%) to middle-aged ones (77/140; 55%) to lung cancer sufferers (34/58; 59%), showing the minimal estimates in elderly non-affected smokers (35/81; 43%) and the maximal ones in the affected non-smokers (7/7, 100%). These data have led to the two groups of conclusions. First, the broad protective role of GSTM1 has been confirmed in this report. In particular, GSTM1-deficiency appeared to reduce the chances of entering an elderly age without a history of malignancy (OR=0.66 (0.42-1.04); P=0.073). Second, the efficiency of 'tumour patients versus elderly donors' comparative analysis has been exemplified. Indeed, the long-debated fact of overrepresentation of GSTM1(-) genotypes among lung cancer sufferers was clearly demonstrated by comparison of the affected individuals to the geriatric controls (OR=1.76 (0.96-3.23); P=0.068), whereas the same patients failed to produce any convincing deviations towards the middle-aged donors (OR=1.16 (0.63-2.14); P=0.641).

L-MYC and GSTM1 polymorphisms are associated with unfavourable clinical parameters of gliomas.

L-MYC and GSTM1 genotypes were analysed in glioma patients (GP) and healthy donors (HD). None of these genes appeared to influence the risk of this disease, however both polymorphisms correlated with unfavourable clinical parameters of gliomas. In particular, S allele of the L-MYC was overrepresented in the relapsed patients (P < 0.05), and GSTM1-null genotype was associated with the advanced tumour grade (P < 0.05). Patients, but not donors, demonstrated frequent combination of SS L-MYC homozygosity with GSTM1(-) variant (P < 0.01 ), as well as a correlation between LL L-MYC homozygosity and GSTM1 (+) genotype (P < 0.05).

Tissue transglutaminase expression in breast carcinomas.

Tissue transglutaminase (tTG) is known to participate in multiple cellular processes, including apoptosis, cellular adhesiveness etc. Alterations of tTG expression could contribute to the development of several categories of diseases, including AIDS, cancer etc. The aim of the study was to test the pattern and relevance of tTG expression in a subset of breast carcinomas. RT-PCR has detected tTG-specific RNA message in 11 out of 25 (44%) breast cancer samples. tTG message was detected in 6/8 (75%) breast carcinomas with high apoptotic index, but only in 5/17 (29%) with the low one (p = 0.03). Immunohistochemical analysis revealed that only 15% of breast carcinomas displayed tTG protein in tumor cells, while the staining of the stromal components occurred in approximately one-half of the tumours tested. Surprisingly, there was no significant association between tTG RNA expression and protein positivity. Moreover, there was no evident relationships between tTG immunostaining and apoptotic index or clinical parameters of breast neoplasms. There are at least 2 alternative explanations for the poor concordance between RNA and protein data. It is likely that the sensitivity of immunohistochemistry is not sufficient to detect functionally relevant tTG enzyme in all breast cancer sections. Otherwise, tTG RNA expression does not always lead to accumulation of its product in the tumor cells, but reflects the transcriptional activation of other pro-apoptotic genes due to common triggering mechanisms.

[Effect of purine nucleosides on human leukocytes in normal conditions and in leukemias]. / Vliianie purinovykh nukleozidov na leikotsity cheloveka v norme i pri leikozakh.

The degree of action of purine nucleosides (adenosine, deoxyadenosine (d-ado) and deoxyguanosine (d-gua] on peripheral blood leukocytes in leukemias has been shown to change, as estimated by their inhibition of the protein biosynthesis. The inhibitory effect of purines on lymphocytes of the CLL patients and on myeloid cells of patients is decreased as compared to the normal cells. On the contrary, blast cells in T-ALL and AML exhibit the increased sensitivity to d-gua and d-ado. The cytotoxicity of d-ado, as compared to that of other nucleosides, is markedly higher against both the normal and leukemic lymphoid and myeloid cells. The relationship between the differences in purine nucleoside action on the normal and leukemic cells and the peculiar features of the nucleotide metabolism in these cells is discussed.

[Interrelation of degradation processes of purine nucleotides and their biosynthetic transformation in the blood cells of patients with acute leukemia]. / Vzaimosviaz' protsessov degradatsii purinovykh nukleotidov i ikh biosinteticheskikh prevrashchenii v kletkakh krovi bol'nykh ostrym leikozom.

It has been shown that the leukemic process shifts the balance of individual enzymatic steps of the purine nucleotide degradation and biosynthesis. In acute lymphoblastic leukosis (ALL) and acute myeloblastic leukosis (AML) the rate of purine degradation, as estimated by the ADA enzyme activity (ES 3.5.4.4.) and PNP (EC 2.4.2.1), exceeds considerably that of their enzymes AMP-DA (EC 3.5.4.6.) and IMP-DH (EC 1.2.1.14.) biosynthesis. The data obtained suggest the existence of differences in the enzymatic program of purine metabolism in the malignant transformation of hematopoietic tissue and in other tumours.

[Amplification of the erbb-2 (Her-2/NEU), erbb-1 (HER-1) and c-myc oncogenes is often combined with the deletion of the short arm of chromosome 17 in human carcinoma]. / Amplifikatsiia onkogenom erbb-2 (HER-2/NEU), erbb-1 (HER-1) i c-myc chasta sochetaetsia s deletsiei korotkogo plecha khromosomy 17 v kartsinomakh u chelovekakh.

Amplification of oncogenes erbb-2, erbb-1, c-myc and losses of heterozygosity (LOH) at chromosomes 11p (probe hras-1), 17p (probe ynz-22) and 17q (probe thh-59) were studied in 165 human tumours (60 breast, 22 ovary, 40 colorectal, 23 lung, and 20 thyroid carcinomas). The correlation (P < 0.01) between the increased copy number of mentioned oncogenes and LOH at 17p was demonstrated for tumours tested: extra copies of these oncogenes were revealed in 11 of 46 DNA specimens with LOH on ynz-22, but only in 3 of 61 without LOH. This correlation was mostly due to frequent combinations between erbb-2 amplification and 17p deletions; the incidence of increased copy number of erbb-1 and c-myc oncogenes was not high enough for final conclusions about the association of their alterations with LOH at chromosome 17p.

[Search for Ki-ras codon 61 mutations in lung adenomas induced in neonatal BALB/c mice with 5-bromodesoxyuridine injection followed by urethane treatment]. / Poisk mutatsii v 61-m kodone onkogena Ki-ras v adenomakh lëgkikh, indutsirovannykh neonatal'nym vvedeniem 5-bromodezoksiuridina i posleduiushchim vozdeistviem uretana u myshei balb/c.

BALD/c mice were injected, s.c., 1 mg 5-bromodeoxyuridine (BDU) on days 1.3 and 7 after birth and/or 0.1 ml 5% solution of urethane, 5 times a day every fourth day, i.p., at the age of 3 months. Lung tumors, mostly adenomas, developed in 67% of males and 56% of females, treated with urethane alone. Tumor frequency in response to BDU + urethane rose to 91% in males and 56% in females; multiple neoplasia increased too. In BDU-treated animals, lung tumors appeared in 13% of males and 25% of females whereas in intact controls-3 and 11%, respectively. DNA isolated from paraffin mounts of tumor tissue was used to identify mutations in codon 61 of Ki-ras oncogene. Polymorphism studies of restriction fragment lengths in PCR products failed to detect CAA CTA and CAA CGA sequence changes in 7 samples of DNA. Our findings do not rule out other mutations of RAS oncogenes in our material. They also suggest that further research focus on Ki-ras codon 12 as well as Ha-ras "hot" triplets.

[Thymidine kinase activity in leukocytes from patients with chronic myeloid leukemia at various periods in the disease]. / Aktivnost' timidinkinazy v leikotsitakh bol'nykh khronicheskim mieloleikozom v razlichnye periody zabolevaniia.

The level of thymidine kinase activity in the premature leukocytes of patients with chronic myeloleukemia during the stable phase was shown to serve as a measure of the disease development. Considerable variations in thymidine kinase activity in blast cells in myeloid and lymphoid blast crises demonstrated that analysis of the enzyme activity might be used in the biochemical diagnosis of blast crisis in chronic myeloleukemia simultaneously with the enzymes of purine metabolism--ADA and PNP. During cell differentiation, the activity of thymidine kinase was decreased and in the myeloid cells the enzymatic activity was much higher of that in lymphoid cells as shown by investigations using blast cells of patients with blast crisis in chronic myeloleukemia, cells K-562, thymocytes, spleen and peripheric blood lymphocytes. Isozyme thymidine kinase I was mainly responsible for the rate of enzymatic activity in premature leukocytes of patients with chronic myeloleukemia regardless of the disease stage.

[Adenosine deaminase, purine nucleoside phosphorylase and ecto-5'-nucleotidase--markers of acute leukemia variants]. / Adenozindezaminaza, purinnukleozidfosforilaza i ékto-5'-nukleotidaza--markery variantov ostrogo leikoza.

Estimation of enzymes participating in degradation of purine nucleotides--adenosine deaminase (ADA), purine nucleoside phosphorylase (PNP), ecto-5'-nucleotidase as well as the ratio of ADA/PNP in leukocytes was shown to be of importance in differential diagnosis of acute lymphoblast leukosis subforms and for identification of a nature of malignized leukocytes clone in acute undifferentiated leukosis. Importance of these analyses is determined by specific differences in distribution of the enzymatic activity in mononuclear cells in T-, non-T-, non-B-cell acute lymphoblast leukosis and acute myeloblast leukosis as well as due to similar level and ratios of these enzymatic activities in most cases of acute undifferentiated leukosis and in acute lymphoblast leukosis.

[S allele of the L-myc oncogene is associated with lung cancer metastases in patients from Moldova]. / [S-allel' onkogena L-myc assotsirovan s metastazirovaniem raka lëgkikh u bol'nykh iz Moldovy]

Race is widely believed to be a factor in the relationship between S allele of L-MYC oncogene and disseminated lung cancer. In particular, the clinical significance of L-MYC genotype was demonstrated in the Japanese while the results for the white US, Australian and Norwegian cohorts were negative. The present study was concerned with distribution of L-MYC oncogene alleles in 43 patients with lung cancer and 77 healthy subjects in Moldova. L and S allele frequency in both groups were nearly identical. However, the SS genotype was registered much more frequently in patients with metastasis (10/28; 36%)(p < 0.05) than in those with localized tumor (0/12). Moreover, overall frequency of S allele was significantly higher in lung cancer patients with node involvement (35/56; 63%)(p < 0.02) than in those with localized tumors (8/24; 33%)(p < 0.02). Finally, a significant correlation was found between S allele occurrence and distant metastases (M1: 19/28; 68%; M0:26/58; 45%)(p < 0.05). Similar data were reported in Russia. (ABSTRACT TRUNCATED)

[Enzymes of purine nucleotide catabolism in lymphocytes in normal states and in chronic lymphoid leukemia]. / Fermenty katabolicheskikh prevrashchenii purinovykh nukleotidov limfotsitov v norme i pri khronicheskom limfoleikoze.

Activities of adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP) as well as their ratio in chronic lymphocytic leukemia (CLL) were found to be several times lower as compared with normal cells and to depend upon the duration and severity of leukemic process. Ratio of ADA and PNP activities in CLL was inverted as compared with those of normal cells; 5'-nucleotidase activity varied within all the stages of the disease from zero values to supernormals. There was a correlation between beneficial effects of treatment of the CLL patients and an increase in ADA and PNP activities in their peripheral lymphocytes.

[Degradation of purines in leukocytes in acute nonlymphoblastic leukemias]. / O degradatsii purinov v leikotsitakh pri ostrykh nelimfoblastnykh leikozakh.

Activities of the enzymes, responsible for degradation of purine nucleotides in leukocytes, were distinctly dissimilar in M1, M2, M4 and M6 variants of acute non-lymphoblastic leukosis studied in 34 patients. Differentiation of leukemic cells was shown to be due to alterations in activity of adenosine deaminase and purine nucleoside phosphorylase, which were oppositely directed as compared with those observed in lymphoblasts under conditions of acute lymphoblast leukosis. Evaluation of activities of adenosine deaminase, purine nucleoside phosphorylase and 5'-nucleotidase is of importance for characteristics of individual variants of acute non-lymphoblastic leukosis and for elucidation of the state of leukemic clone differentiation, which may affect the efficiency of the therapeutic measures used.

[Enzymatic markers in chronic myeloleukemia and their importance for identifying a blast crisis]. / Enzimaticheskie markery pri khronicheskom mieloleikoze i ikh znachenie dlia identifikatsii blastnogo kriza.

The paper summarizes data on the activity of adenosine deaminase and purine nucleoside phosphorylase which contribute to purine nucleotide degradation. The enzyme activity was studied in leukocytes of varying degree of differentiation obtained from 29 cases with chronic phase of chronic myeloid leukemia (CML), 19 patients with acute phase of the disease and from blasts of 32 cases with CML-associated blast crisis. In CML patients, lymphocytes of leukemic clones showed various levels of activity of the enzymes. Myeloid and lymphoid blast crises proved biochemically heterogeneous. The possibility to establish the nature of blast crisis in CML on the basis of profile of adenosine deaminase and purine nucleoside phosphorylase in blasts is discussed.