Colorectal cancer (CRC) is a disease with constantly increasing incidence and high mortality. The treatment efficacy could be curtailed by drug resistance resulting from poor drug penetration into tumor tissue and the tumor-specific microenvironment, such as hypoxia and acidosis. Furthermore, CRC tumors can be exposed to different pH depending on the position in the intestinal tract. CRC tumors often share upregulation of the Akt signaling pathway. In this study, we investigated the role of external pH in control of cytotoxicity of perifosine, the Akt signaling pathway inhibitor, to CRC cells using 2D and 3D tumor models. In 3D settings, we employed an innovative strategy for simultaneous detection of spatial drug distribution and biological markers of proliferation/apoptosis using a combination of mass spectrometry imaging and immunohistochemistry. In 3D conditions, low and heterogeneous penetration of perifosine into the inner parts of the spheroids was observed. The depth of penetration depended on the treatment duration but not on the external pH. However, pH alteration in the tumor microenvironment affected the distribution of proliferation- and apoptosis-specific markers in the perifosine-treated spheroid. Accurate co-registration of perifosine distribution and biological response in the same spheroid section revealed dynamic changes in apoptotic and proliferative markers occurring not only in the perifosine-exposed cells, but also in the perifosine-free regions. Cytotoxicity of perifosine to both 2D and 3D cultures decreased in an acidic environment below pH 6.7. External pH affects cytotoxicity of the other Akt inhibitor, MK-2206, in a similar way. Our innovative approach for accurate determination of drug efficiency in 3D tumor tissue revealed that cytotoxicity of Akt inhibitors to CRC cells is strongly dependent on pH of the tumor microenvironment. Therefore, the effect of pH should be considered during the design and pre-clinical/clinical testing of the Akt-targeted cancer therapy.

• Klíčová slova
• Akt kinase, alkalization, colorectal cancer, lactic acidosis, mass spectrometry imaging, perifosine, signal co-registration, tumor environment,
• Publikační typ
• časopisecké články MeSH

Neuroblastoma is the most common extracranial solid tumour of infancy. Pathological activation of glucose consumption, glycolysis and glycolysis-activating Akt kinase occur frequently in neuroblastoma cells, and these changes correlate with poor prognosis of patients. Therefore, several inhibitors of glucose utilization and the Akt kinase activity are in preclinical trials as potential anti-cancer drugs. However, metabolic plasticity of cancer cells might undermine efficacy of this approach. In this work, we identified oxidative phosphorylation as compensatory mechanism preserving viability of neuroblastoma cells with inhibited glucose uptake/Akt kinase. It was oxidative phosphorylation that maintained intracellular level of ATP and proliferative capacity of these cells. The oxidative phosphorylation inhibitors (rotenone, tetrathiomolybdate) synergized with inhibitor of the Akt kinase/glucose uptake in down-regulation of both viability of neuroblastoma cells and clonogenic potential of cells forming neuroblastoma spheroids. Interestingly, tetrathiomolybdate acted as highly specific inhibitor of oxygen consumption and activator of lactate production in neuroblastoma cells, but not in normal fibroblasts and neuronal cells. Moreover, the reducing effect of tetrathiomolybdate on cell viability and the level of ATP in the cells with inhibited Akt kinase/glucose uptake was also selective for neuroblastoma cells. Therefore, efficient elimination of neuroblastoma cells requires inhibition of both glucose uptake/Akt kinase and oxidative phosphorylation activities. The use of tetrathiomolybdate as a mitochondrial inhibitor contributes to selectivity of this combined treatment, preferentially targeting neuroblastoma cells.

• Klíčová slova
• Akt kinase, cell viability, glycolysis, metabolic plasticity, neuroblastoma, oxygen consumption, tetrathiomolybdate,
• MeSH
• adenosintrifosfát metabolismus   MeSH
• buněčné dýchání účinky léků   MeSH
• down regulace účinky léků   MeSH
• fibroblasty účinky léků   metabolismus   MeSH
• fosforylace účinky léků   MeSH
• glukosa metabolismus   MeSH
• inhibitory proteinkinas farmakologie   MeSH
• kyselina mléčná biosyntéza   MeSH
• lidé MeSH
• mitochondrie účinky léků   metabolismus   MeSH
• molybden farmakologie   MeSH
• myši inbrední C57BL MeSH
• nádorové buněčné linie MeSH
• neuroblastom enzymologie   metabolismus   patologie   MeSH
• neurony účinky léků   metabolismus   MeSH
• oxidativní fosforylace účinky léků   MeSH
• protoonkogenní proteiny c-akt antagonisté a inhibitory   metabolismus   MeSH
• spotřeba kyslíku účinky léků   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adenosintrifosfát MeSH
• glukosa MeSH
• inhibitory proteinkinas MeSH
• kyselina mléčná MeSH
• molybden MeSH
• protoonkogenní proteiny c-akt MeSH
• tetrathiomolybdate MeSH Prohlížeč