Molecular Protein and Expression Profile in the Primary Tumors of Clear Cell Renal Carcinoma and Metastases.

Metastasis involves the spread of cancer cells from the primary tumor to surrounding tissues and distant organs and is the primary cause of cancer morbidity and mortality. The aim of the study was the determination of change in molecular factors expression in primary kidney cancers (ccRCC) and metastatic sites. In total, 62 patients with RCC were enrolled in the study. The mRNA levels of molecular markers were studied by real-time PCR, and the content of the studied parameters was determined by Western blotting and ELISA. The features in the intracellular signal metabolites in the series of normal renal parenchyma, tumor tissue of localized, disseminated kidney cancer and metastatic tissue were studied. A decrease in some indicators in the tissue of the metastatic lesion was noted. Protein products of transcription factors HIF-1, CAIX, PTEN and activated AKT kinase, as well as expression of the VEGFR2 receptor and m-TOR protein kinase were revealed to be reduced in the metastatic sites. In addition, some indicators increased in metastasis: the protein levels of NF-κB p 50, NF-κB p 65, HIF-2, VEGF, VEGFR2, m-TOR and mRNA of HIF-1, CAIX, PTEN and PDK. There were indicators with multidirectional changes. HIF-1, CAIX, PTEN, VEGFR2 and m-TOR mRNA: VEGFR2, m-TOR, HIF-1, CAIX, PTEN and PDK had an opposite change in protein content and mRNA level. PTEN loss resulted in the downstream activation of AKT/mTOR signaling in secondary cancer lesions and determined the overall ccRCC patient's survival. The AKT/mTOR signaling cascade activation was found in the primary kidney tumors. The PTEN content and mRNA level were correlated with total AKT, GSK-3ß, the 70S 6 kinases and AKT expression.

Molecular Mechanism of Resistance to Chemotherapy in Gastric Cancers, the Role of Autophagy.

Gastric cancer (GC) is biologically and genetically heterogeneous with complex carcinogenesis at the molecular level. Despite the application of multiple approaches in the GC treatment, its 5-year survival is poor. A major limitation of anti-cancer drugs application is intrinsic or acquired resistance, especially to chemotherapeutical agents. It is known that the effectiveness of chemotherapy remains debatable and varies according to the molecular type of GC. Chemotherapy has an established role in the management of GC. Perioperative chemotherapy or postoperative chemotherapy is applied for localized ones. Most of the advanced GC patients have a poor response to treatment and unfavorable outcomes with standard therapies. Resistance substantially limits the depth and duration of clinical responses to targeted anticancer therapies. Through the use of complementary experimental approaches, investigators have revealed that cancer cells can achieve resistance through adaptation or selection driven by specific genetic, epigenetic, or microenvironmental alterations. Ultimately, these diverse alterations often lead to the activation of MAPK, AKT/mTOR, and Wnt/ß-catenin signaling pathways that, when co-opted, enable cancer cells to survive drug treatments. We have summarized the mechanisms of resistance development to cisplatin, 5-fluorouracil, and multidrug resistance in the GC management. The complexity of molecular targets and components of signaling cascades altered in the resistance development results in the absence of significant benefits in GC treatment, and its efficacy remains low. The universal process responsible for the failure in the multimodal approach in GC treatment is autophagy. Its dual role in oncogenesis is the most unexplored issue. We have discussed the possible mechanism of autophagy regulation upon the action of endogenous factors and drugs. The experimental data obtained in the cultured GC cells need further verification. To overcome the cancer resistance and to prevent autophagy as the main reason of ineffective treatment, it is suggested the concept of the direct influence of autophagy molecular markers followed by the standard chemotherapy. Dozen of studies have focused on finding the rationale for the benefits of such complex therapy. The perspectives in the molecular-based management of GC are associated with the development of molecular markers predicting the protective autophagy initiation and search for novel targets of effective anticancer therapy.

[Targeting of the AKT/m-TOR Pathway: Biomarkers of Resistance to Cancer Therapy--
AKT/m-TOR Pathway and Resistance to Cancer Therapy].

Resistance to cancer therapy continues to be a major limitation for the successful treatment of cancer. There are many published studies on therapy resistance in breast and prostate cancers; however, there are currently no data on molecular markers associated with resistance. The conflicting data were reported regarding the AKT/m-TOR signaling pathway components as markers predicting resistance. The AKT/m-TOR signaling pathway is involved in the development of many human cancers; its activation is related to cell proliferation, angiogenesis, apoptosis, as well as to therapy resistance. Molecular alterations in the AKT/m-TOR signaling pathway provide a platform to identify universal markers associated with the development of resistance to cancer therapy.