Circulating tumor cells in breast cancer: functional heterogeneity, pathogenetic and clinical aspects

Each patient has a unique history of cancer ecosystem development, resulting in intratumor heterogeneity. In order to effectively kill the tumor cells by chemotherapy, dynamic monitoring of driver molecular alterations is necessary to detect the markers for acquired drug resistance and find the new therapeutic targets. To perform the therapeutic monitoring, frequent tumor biopsy is needed, but it is not always possible due to small tumor size or its regression during the therapy or tumor inaccessibility in advanced cancer patients. Liquid biopsy appears to be a promising approach to overcome this problem, providing the testing of circulating tumor cells (CTC) and/or tumor-specific circulating nucleic acids. Their genomic characteristics make it possible to assess the clonal dynamics of tumors, comparing it with the clinical course and identification of driver mutation that confer resistance to therapy. The main attention in this review is paid to CTC. The biological behavior of the tumor is determined by specific cancer-promoting molecular and genetic alterations of tumor cells, and by the peculiarities of their interactions with the microenvironment that can result in the presence of wide spectrum of circulating tumor clones with various properties and potentialities to contribute to tumor progression and response to chemotherapy and prognostic value. Indeed, data on prognostic or predictive value of CTC are rather contradictory, because there is still no standard method of CTC identification, represented by different populations manifesting various biological behavior as well as different potency to metastasis. Circulating clasters of CTC appear to have essentially greater ability to metastasize in comparison with single CTC, as well as strong association with worse prognosis and chemoresistance in breast cancer patients. The Food and Drug Administration (USA) has approved the CTC-based prognostic test for clinical application in patients with advanced breast cancer. Prospective clinical trials have demonstrated that measuring changes in CTC numbers during treatment is useful for monitoring therapy response in breast cancer patients. Molecular and genetic analysis of CTC gives the opportunity to have timely information on emergence of resistant tumor clones and may shed light on the new targets for pathogenetic antitumor therapy

Multidimensional visualization for the immune system state presentation in breast cancer patients

The immune system is a complex organization system possessing its hierarchical structure of morphological and functional elements united into an integral unity. Therefore the immune system state should be characterized as an integral unity. The use of the NovoSpark Visualisation approach (Canada) to multidimensional data visualization provides the visual image representing the immune system state as an integral unity. This uniform visual characteristic is formed by values of individual immunological parameters in every person. The curves appropriating the immune system states in breast cancer patients with and without cancer progression (hematogenous metastases) during a 3-year follow-up are located in disjoint areas of the multidimensional data space. The obtained data suggest that the immune system greatly influences the course and outcome of breast cancer. In prospect this approach can be useful for a breast cancer outcome prognosis

Smoking-related DNA adducts as potential diagnostic markers of lung cancer: new perspectives

In recent years, the new direction such as identification of informative circulating markers reflecting molecular genetic changes in the DNA of tumor cells was actively developed. Smoking-related DNA adducts are very promising research area, since they indicate high pathogenetic importance in the lung carcinogenesis and can be identified in biological samples with high accuracy and reliability using highly sensitive mass spectrometry methods (TOF/TOF, TOF/MS, MS/MS). The appearance of DNA adducts in blood or tissues is the result of the interaction of carcinogenic factors, such as tobacco constituents, and the body reaction which is determined by individual characteristics of metabolic and repair systems. So, DNA adducts may be considered as a cumulative mirror of heterogeneous response of different individuals to smoking carcinogens, which finally could determine the risk for lung cancer. This review is devoted to analysis of the role of DNA adducts in lung carcinogenesis in order to demonstrate their usefulness as cancer associated markers. Currently, there are some serious limitations impeding the widespread use of DNA adducts as cancer biomarkers, due to failure of standardization of mass spectrometry analysis in order to correctly measure the adduct level in each individual. However, it is known that all DNA adducts are immunogenic, their accumulation over some threshold concentration leads to the appearance of long-living autoantibodies. Thus, detection of an informative pattern of autoantibodies against DNA adducts using innovative multiplex ELISA immunoassay may be a promising approach to find lung cancer at an early stage in high-risk groups (smokers, manufacturing workers, urban dwellers)

Frequency of EGFR mutations in non-small cell lung cancer patients: screening data from West Siberia

BACKGROUN

Circulating tumor cells in breast cancer: functional heterogeneity, pathogenetic and clinical aspects

Each patient has a unique history of cancer ecosystem development, resulting in intratumor heterogeneity. In order to effectively kill the tumor cells by chemotherapy, dynamic monitoring of driver molecular alterations is necessary to detect the markers for acquired drug resistance and find the new therapeutic targets. To perform the therapeutic monitoring, frequent tumor biopsy is needed, but it is not always possible due to small tumor size or its regression during the therapy or tumor inaccessibility in advanced cancer patients. Liquid biopsy appears to be a promising approach to overcome this problem, providing the testing of circulating tumor cells (CTC) and/or tumor-specific circulating nucleic acids. Their genomic characteristics make it possible to assess the clonal dynamics of tumors, comparing it with the clinical course and identification of driver mutation that confer resistance to therapy. The main attention in this review is paid to CTC. The biological behavior of the tumor is determined by specific cancer-promoting molecular and genetic alterations of tumor cells, and by the peculiarities of their interactions with the microenvironment that can result in the presence of wide spectrum of circulating tumor clones with various properties and potentialities to contribute to tumor progression and response to chemotherapy and prognostic value. Indeed, data on prognostic or predictive value of CTC are rather contradictory, because there is still no standard method of CTC identification, represented by different populations manifesting various biological behavior as well as different potency to metastasis. Circulating clasters of CTC appear to have essentially greater ability to metastasize in comparison with single CTC, as well as strong association with worse prognosis and chemoresistance in breast cancer patients. The Food and Drug Administration (USA) has approved the CTC-based prognostic test for clinical application in patients with advanced breast cancer. Prospective clinical trials have demonstrated that measuring changes in CTC numbers during treatment is useful for monitoring therapy response in breast cancer patients. Molecular and genetic analysis of CTC gives the opportunity to have timely information on emergence of resistant tumor clones and may shed light on the new targets for pathogenetic antitumor therapy

Multidimensional visualization for the immune system state presentation in breast cancer patients

The immune system is a complex organization system possessing its hierarchical structure of morphological and functional elements united into an integral unity. Therefore the immune system state should be characterized as an integral unity. The use of the NovoSpark Visualisation approach (Canada) to multidimensional data visualization provides the visual image representing the immune system state as an integral unity. This uniform visual characteristic is formed by values of individual immunological parameters in every person. The curves appropriating the immune system states in breast cancer patients with and without cancer progression (hematogenous metastases) during a 3-year follow-up are located in disjoint areas of the multidimensional data space. The obtained data suggest that the immune system greatly influences the course and outcome of breast cancer. In prospect this approach can be useful for a breast cancer outcome prognosis

Smoking-related DNA adducts as potential diagnostic markers of lung cancer: new perspectives

In recent years, the new direction such as identification of informative circulating markers reflecting molecular genetic changes in the DNA of tumor cells was actively developed. Smoking-related DNA adducts are very promising research area, since they indicate high pathogenetic importance in the lung carcinogenesis and can be identified in biological samples with high accuracy and reliability using highly sensitive mass spectrometry methods (TOF/TOF, TOF/MS, MS/MS). The appearance of DNA adducts in blood or tissues is the result of the interaction of carcinogenic factors, such as tobacco constituents, and the body reaction which is determined by individual characteristics of metabolic and repair systems. So, DNA adducts may be considered as a cumulative mirror of heterogeneous response of different individuals to smoking carcinogens, which finally could determine the risk for lung cancer. This review is devoted to analysis of the role of DNA adducts in lung carcinogenesis in order to demonstrate their usefulness as cancer associated markers. Currently, there are some serious limitations impeding the widespread use of DNA adducts as cancer biomarkers, due to failure of standardization of mass spectrometry analysis in order to correctly measure the adduct level in each individual. However, it is known that all DNA adducts are immunogenic, their accumulation over some threshold concentration leads to the appearance of long-living autoantibodies. Thus, detection of an informative pattern of autoantibodies against DNA adducts using innovative multiplex ELISA immunoassay may be a promising approach to find lung cancer at an early stage in high-risk groups (smokers, manufacturing workers, urban dwellers)

New variants in the BRCA1 gene in Buryat Mongol breast cancer patients: Report from two families

BACKGROUND: The BRCA1 mutations that are endemic to the Slavic population of Russia have not been identified among indigenous peoples, including the Buryats, Tuvinians and Altaians with hereditary breast cancer. OBJECTIVE: This study was aimed to identify the mutations that are responsible for the occurrence of hereditary breast cancer in the indigenous population of the Republic of Buryatia. METHODS: Mutations in the BRCA1 gene were identified in blood samples by Sanger-based sequencing. RESULTS: We identified 11 polymorphisms (10 SNPs and 1 Indel) and 6 new unclassified sequence variants in the BRCA1 gene. In our study three new sequence variants (c.321T>A, c.366T>A, c.4357+2T>A) were found in position of previously described polymorphisms in dbSNPs: rs80357544 (c.321delT), rs190900046 (c.366T>G), and rs80358152 (c.4357+2T>C), respectively. Other three new sequence variants (c.3605A>G, c.1998A>C, and c.80+13A>C) have not been previously described in dbSNP, BIC and Human Gene Mutation Databases. CONCLUSIONS: We described six new sequence variants that have never been published in the literature or databases. Further studies are required to confirm the impact of new sequence variants on the risk of breast cancer in the Buryat Mongol population

New variants in the BRCA1 gene in Buryat Mongol breast cancer patients: Report from two families

BACKGROUND: The BRCA1 mutations that are endemic to the Slavic population of Russia have not been identified among indigenous peoples, including the Buryats, Tuvinians and Altaians with hereditary breast cancer. OBJECTIVE: This study was aimed to identify the mutations that are responsible for the occurrence of hereditary breast cancer in the indigenous population of the Republic of Buryatia. METHODS: Mutations in the BRCA1 gene were identified in blood samples by Sanger-based sequencing. RESULTS: We identified 11 polymorphisms (10 SNPs and 1 Indel) and 6 new unclassified sequence variants in the BRCA1 gene. In our study three new sequence variants (c.321T>A, c.366T>A, c.4357+2T>A) were found in position of previously described polymorphisms in dbSNPs: rs80357544 (c.321delT), rs190900046 (c.366T>G), and rs80358152 (c.4357+2T>C), respectively. Other three new sequence variants (c.3605A>G, c.1998A>C, and c.80+13A>C) have not been previously described in dbSNP, BIC and Human Gene Mutation Databases. CONCLUSIONS: We described six new sequence variants that have never been published in the literature or databases. Further studies are required to confirm the impact of new sequence variants on the risk of breast cancer in the Buryat Mongol population

Frequency of EGFR mutations in non-small cell lung cancer patients: screening data from West Siberia

BACKGROUN