The phenomenon of multi-drug resistance in the treatment of malignant tumors

Multi-drug resistance (MDR) is a condition when there is broad cross-resistance of cells to various agents which are different in structure and effect. Modern perceptions on mechanisms of MDR development in malignant tumors have been considered, in particular, in tre­ating breast cancer. Physiological functions and contribution to MDR development of ABC-transporter protein families have been described. The role of activation of glutathione system enzymes and apoptosis-regulating proteins in MDR formation has been shown. Key Words: multi-drug resistance, ABC-transporters, glutathione system, apoptosis-controlling genes

Different morphological structures of breast tumors demonstrate individual drug resistance gene expression profiles

Aim: To identify gene expression profiles involved in drug resistance of different morphological structures (tubular, alveolar, solid, trabecular, and discrete) presented in breast cancer. Material and Methods: Ten patients with luminal breast cancer have been included. A laser microdissection-assisted microarrays and qRT-PCR were used to perform whole-transcriptome profiling of different morphological structures, to select differentially expressed drug response genes, and to validate their expression. Results: We found 27 differentially expressed genes (p < 0.05) encoding drug uptake (SLC1A3, SLC23A2, etc.) and efflux (ABCC1, ABCG1, etc.) transporters, drug targets (TOP2A, TYMS, and Tubb3), and proteins that are involved in drug detoxification (NAT1 and ALDH1B1), cell cycle progression (CCND1, AKT1, etc.), apoptosis (CASP3, TXN2, etc.), and DNA repair (BRCA1 and USP11). Each type of structures showed an individual gene expression profile related to resistance and sensitivity to anticancer drugs. However, most of the genes (19/27; p < 0.05) were expressed in alveolar structures. Functional enrichment analysis showed that drug resistance is significantly associated with alveolar structures. Other structures demonstrated the similar number (10–13 out of 27) of expressed genes; however, the spectrum of resistance and sensitivity to different anticancer drugs varied. Conclusion: Different morphological structures of breast cancer show individual expression of drug resistance genes. Key Words: breast cancer, tumor heterogeneity, gene expression, chemotherapy, drug resistance

Different morphological structures of breast tumors demonstrate individual drug resistance gene expression profiles

Aim: To identify gene expression profiles involved in drug resistance of different morphological structures (tubular, alveolar, solid, trabecular, and discrete) presented in breast cancer. Material and Methods: Ten patients with luminal breast cancer have been included. A laser microdissection-assisted microarrays and qRT-PCR were used to perform whole-transcriptome profiling of different morphological structures, to select differentially expressed drug response genes, and to validate their expression. Results: We found 27 differentially expressed genes (p < 0.05) encoding drug uptake (SLC1A3, SLC23A2, etc.) and efflux (ABCC1, ABCG1, etc.) transporters, drug targets (TOP2A, TYMS, and Tubb3), and proteins that are involved in drug detoxification (NAT1 and ALDH1B1), cell cycle progression (CCND1, AKT1, etc.), apoptosis (CASP3, TXN2, etc.), and DNA repair (BRCA1 and USP11). Each type of structures showed an individual gene expression profile related to resistance and sensitivity to anticancer drugs. However, most of the genes (19/27; p < 0.05) were expressed in alveolar structures. Functional enrichment analysis showed that drug resistance is significantly associated with alveolar structures. Other structures demonstrated the similar number (10–13 out of 27) of expressed genes; however, the spectrum of resistance and sensitivity to different anticancer drugs varied. Conclusion: Different morphological structures of breast cancer show individual expression of drug resistance genes. Key Words: breast cancer, tumor heterogeneity, gene expression, chemotherapy, drug resistance

Heterogeneity of premetastatic niches gene expression in breast cancer cells

Aim. To investigate the expression of the genes TGFB1, TNF, CSF1, CSF2, VEGFA and HIF1A in the patients with invasive breast carcinoma of no special type considering the intratumoral morphological heterogeneity. Methods. The technology of laser capture microdissection PALM was used to isolate five types of morphological tumor structures from three patients with invasive carcinoma of no special type (IC NST), luminal A subtype, T1-2NxMx. The level of expression of the cytokine (TNF), growth factor genes (TGFB1, CSF1, CSF2, VEGFA) and the HIF1A gene was assessed in the samples obtained using real-time PCR, TaqMan-probes and specific oligonucleotides. Results. The study demonstrated the absence of the expression of the growth factor gene CSF2 in tumor cells of IC NST, and the expression of the gene CSF1, independent from the metastasis status and tumor structure type. The prevalence of the expression of the genes VEGFA and TGFB1 was revealed in the alveolar and solid structures along with the rare expression of the gene TNF. Conclusions. The expression of pre-metastatic niche genes in the tumors of patients with IC NST is heterogeneous. The hypoxia-mediated change in the cytokine gene expression may be expected in the alveolar and solid structures, which ultimately results in the formation of microenvironment, facilitating tumor growth and the formation of tumor metastatic potential.Мета. Вивчення експресії генів TGFB1, TNF, CSF1, CSF2, VEGFA і HIF1A у хворих з інвазивною карциномою молочної залози неспецифічного типу з урахуванням внутрішньопухлинної морфологічної гетерогенності. Методи. Із застосуванням технології лазерної мікродисекції PALM проводилося виділення п’яти типів морфологічних структур пухлини від трьох хворих інвазивною карциномою молочної залози неспецифічного типу (IC NST), люмінальний А підтип, T1-2NxMx. В отриманих зразках методом ПЛР в режимі «реального часу» з використанням TaqMan-зондів і специфічних олігонуклеотидів було проведено оцінку рівня експресії генів цитокінів (TGFB1 і TNF), генів факторів росту (CSF1, CSF2, VEGFA) і гена HIF1A. Результати. Проведене дослідження показало відсутність експресії гена ростового фактора CSF2 в пухлинних клітинах IC NST, а також незалежну від статусу метастазування і типу структури експресію гена CSF1. Було виявлено переважання експресії генів VEGFA і TGFB1 в альвеолярних і солідних структурах, а також рідкісна експресія гена TNF. Висновки. Експресія генів преметастатичних ніш в пухлинах хворих з IC NST гетерогенна. В альвеолярних і солідних структурах можна очікувати опосередковану гіпоксією зміну експресії генів хемоаттрактантів, що, в кінцевому рахунку, веде до формування мікрооточення, що сприяє зростанню пухлини і формуванню метастатичного потенціалу пухлини.Цель. Изучение экспрессии генов TGFB1, TNF, CSF1, CSF2, VEGFA и HIF1A у больных инвазивной карциномой молочной железы неспецифического типа с учетом внутриопухолевой морфологической гетерогенности. Методы. С применением технологии лазерной микродиссекции PALM проводилось выделение пяти типов морфологических структур опухоли от 3 больных инвазивной карциномой молочной железы неспецифического типа (IC NST), люминальный А подтип, T1-2NxMx. В полученных образцах методом ПЦР в режиме «реального времени» с использованием TaqMan-зондов и специфических олигонуклеотидов была проведена оценка уровня экспрессии генов цитокинов (TNF), генов факторов роста (TGFB1, CSF1, CSF2, VEGFA) и гена HIF1A. Результаты. Проведенное исследование показало отсутствие экспрессии гена ростового фактора CSF2 в опухолевых клетках IC NST, а также независимую от статуса метастазирования и типа структуры экспрессию гена CSF1. Было выявлено преобладание экспрессии генов VEGFA и TGFB1 в альвеолярных и солидных структурах, а также редкая экспрессия гена TNF. Выводы. Экспрессия генов преметастатических ниш в опухоли у больных IC NST гетерогенна. В альвеолярных и солидных структурах можно ожидать опосредованное гипоксией изменение экспрессии генов цитокинов, в конечном счете, ведущее к формированию микроокружения, способствующего росту опухоли и формированию метастатического потенциала опухоли

DIFFERENT MORPHOLOGICAL STRUCTURES OF BREAST TUMORS DEMONSTRATE INDIVIDUAL DRUG RESISTANCE GENE EXPRESSION PROFILES

Aim: To identify gene expression profiles involved in drug resistance of different morphological structures (tubular, alveolar, solid, trabecular, and discrete) presented in breast cancer. Material and Methods: Ten patients with luminal breast cancer have been included. A laser microdissection-assisted microarrays and qRT-PCR were used to perform whole-transcriptome profiling of different morphological structures, to select differentially expressed drug response genes, and to validate their expression. Results: We found 27 differentially expressed genes (p < 0.05) encoding drug uptake (SLC1A3, SLC23A2, etc.) and efflux (ABCC1, ABCG1, etc.) transporters, drug targets (TOP2A, TYMS, and Tubb3), and proteins that are involved in drug detoxification (NAT1 and ALDH1B1), cell cycle progression (CCND1, AKT1, etc.), apoptosis (CASP3, TXN2, etc.), and DNA repair (BRCA1 and USP11). Each type of structures showed an individual gene expression profile related to resistance and sensitivity to anticancer drugs. However, most of the genes (19/27; p < 0.05) were expressed in alveolar structures. Functional enrichment analysis showed that drug resistance is significantly associated with alveolar structures. Other structures demonstrated the similar number (10–13 out of 27) of expressed genes; however, the spectrum of resistance and sensitivity to different anticancer drugs varied. Conclusion: Different morphological structures of breast cancer show individual expression of drug resistance genes. Key Words: breast cancer, tumor heterogeneity, gene expression, chemotherapy, drug resistance

Development of novel monoclonal antibodies for evaluation of transmembrane prostate androgen-induced protein 1 (TMEPAI) expression patterns in gastric cancer.

Transmembrane prostate androgen-induced protein 1 (TMEPAI) is a single-span membrane protein, functionally involved in transforming growth factor beta signaling pathway. The particular protein presented in cells in three isoforms, which differs in the length of the soluble N-terminal extracellular domain, making it challenging for the immunochemical recognition. By using quantitative real-time polymerase chain reaction, we identified significant upregulation of PMEPA1 gene expression in malignant tissues of patients with gastric adenocarcinoma. The main part of commercially available anti-TMEPAI antibodies are having polyclonal nature or not suitable for immunocytochemical localization of target protein in tissue specimens. Hence, we decide to generate a set of novel rat monoclonal antibodies (mAb) directed against conservative C-terminal cytoplasmic epitope. Immunoblotting analysis showed that monoclonal antibodies, 2E1, 6C6, and 10A7 were able to recognize specifically target protein in transiently transfected HEK293T and CHO-K1 cells. Especially established mAb, named 10A7, showed the excellent binding ability to target protein in immunohistochemistry. By using developed antibodies, we observed pronounced expression of TMEPAI in normal gastric epithelial cells while tumor cells from gastric adenomas, and adenocarcinoma samples were mostly negative for target protein expression. Also, we found that gastric epithelium cells lose the TMEPAI expression concurrently with severe dysplasia progression, which probably caused by a mechanism involving specific microRNA

Tumor-associated macrophages in human breast cancer produce new monocyte attracting and pro-angiogenic factor YKL-39 indicative for increased metastasis after neoadjuvant chemotherapy.

It is undeniably one of the greatest findings in biology that (with some very minor exceptions) every cell in the body possesses the whole genetic information needed to generate a complete individual. Today, this concept has been so thoroughly assimilated that we struggle to still see how surprising this finding actually was: all cellular phenotypes naturally occurring in one person are generated from genetic uniformity, and thus are per definition epigenetic. Transcriptional mechanisms are clearly critical for developing and protecting cell identities, because a mis-expression of few or even single genes can efficiently induce inappropriate cellular programmes. However, how transcriptional activities are molecularly controlled and which of the many known epigenomic features have causal roles remains unclear. Today, clarification of this issue is more pressing than ever because profiling efforts and epigenome-wide association studies (EWAS) continuously provide comprehensive datasets depicting epigenomic differences between tissues and disease states. In this commentary, we propagate the idea of a widespread follow-up use of epigenome editing technology in EWAS studies. This would enable them to address the questions of which features, where in the genome, and which circumstances are essential to shape development and trigger disease states