From sufferers also recommend that TKTL1 plays a vital role in cancer migration. Langbein and his co-workers (2006) found that strong TKTL1 activity was observed in invasive tumors, whereas no or weak activity of TKTL1 was detected in non-invasive colon carcinomas. In addition they discovered that improved TKTL1 protein expression was observed in tumor tissue of all sufferers with metastasized kidney cancer, whereas no expression or weak expression in non-progressing tumors.99 Finally, a current study showed that overexpression of TKTL1 induced the expression of HIF-1a in vivo and in vitro. Conversely, gene silence of TKTL1 by siRNA substantially decreased the HIF-1a level.111 HIF-1, a transcriptional factor, regulates the transcription of hundreds of genes that encode proteins involved in just about every aspect of cancer biology, like cell proliferation, division, migration, invasion, and metastasis (Fig. four).31 Taken collectively, the enzymes that function in pentose phosphate pathway could have an effect on tumor cell migration and tumor invasion through several mechanisms.No prospective conflicts of interest have been disclosed.AcknowledgmentsWe thank Dr Ceshi Chen (Kunming Institute of Zoology, Chinese Academy of Science) for discussion and reading in the manuscript. This function was supported by a starting fund from Nanchang University.21. Szpaderska AM, Frankfater A. An intracellular form of cathepsin B contributes to invasiveness in cancer. Cancer Res 2001; 61:3493-500; PMID:11309313 22. Tedone T, Correale M, Barbarossa G, Casavola V, Paradiso A, Reshkin SJ. Release in the aspartyl protease cathepsin D is associated with and facilitates human breast cancer cell invasion. FASEB J 1997; 11:785-92; PMID:9271363 23. Mohamed MM, Sloane BF. Cysteine cathepsins: multifunctional enzymes in cancer.(±)-Naringenin medchemexpress Nat Rev Cancer 2006; six:764-75; PMID:16990854; http://dx.doi. org/10.1038/nrc1949 24. Gatenby RA, Gawlinski ET, Gmitro AF, Kaylor B, Gillies RJ. Acid-mediated tumor invasion: a multidisciplinary study. Cancer Res 2006; 66:5216-23; PMID:16707446; http://dx.doi.org/10.1158/00085472.CAN-05-4193 25. Goetze K, Walenta S, Ksiazkiewicz M, KunzSchughart LA, Mueller-Klieser W. Lactate enhances motility of tumor cells and inhibits monocyte migration and cytokine release. Int J Oncol 2011; 39:453-63; PMID:21617859 26. Walenta S, Wetterling M, Lehrke M, Schwickert G, Sundf K, Rofstad EK, Mueller-Klieser W.Hexapeptide-12 Purity & Documentation High lactate levels predict likelihood of metastases, tumor recurrence, and restricted patient survival in human cervical cancers.PMID:24883330 Cancer Res 2000; 60:916-21; PMID:10706105 27. Yokota H, Guo J, Matoba M, Higashi K, Tonami H, Nagao Y. Lactate, choline, and creatine levels measured by vitro 1H-MRS as prognostic parameters in individuals with non-small-cell lung cancer. J Magn Reson Imaging 2007; 25:992-9; PMID:17410583; http:// dx.doi.org/10.1002/jmri.20902 28. Hashimoto T, Hussien R, Oommen S, Gohil K, Brooks GA. Lactate sensitive transcription element network in L6 cells: activation of MCT1 and mitochondrial biogenesis. FASEB J 2007; 21:260212; PMID:17395833; http://dx.doi.org/10.1096/ fj.07-8174com 29. Lu H, Forbes RA, Verma A. Hypoxia-inducible factor 1 activation by aerobic glycolysis implicates the Warburg effect in carcinogenesis. J Biol Chem 2002; 277:231115; PMID:11943784; http://dx.doi.org/10.1074/jbc. M202487200 30. Lu H, Dalgard CL, Mohyeldin A, McFate T, Tait AS, Verma A. Reversible inactivation of HIF-1 prolyl hydroxylases makes it possible for cell metabolism to handle basal HIF-1. J Biol Chem 2005; 2.
