Transketolase-like protein 1 confers resistance to serum withdrawal in vitro.
Transketolase-like protein 1 (TKTL1) is a member of the family of transketolase enzymes of which the founder member transketolase (TKT) is known to play a central role in the non-oxidative part of the pentose phosphate pathway. According to several publications TKTL1 is the only family member, whose expression is substantially de-regulated in a variety of solid tumours. Over-expression of TKTL1 correlates with poor prognosis of cancer patients and TKTL1 itself represents a potential therapeutic target owing to its possible involvement in the regulation of the proliferation and metabolism of cancer cells. We show that exogenously expressed TKTL1 provides HEK293 cells with moderate growth advantages under standard culture conditions, while protecting cells from growth factor withdrawal-induced apoptosis. Importantly, we identified TKTL1 with the JFC12T10 antibody as a 65kDa protein, which was however absent in most tumour cell lines tested. Primary head and neck squamous cell carcinomas of various localisations were characterised by a focal pattern with single cells strongly expressing TKTL1, rather than by a homogeneous expression pattern within the tumour mass.
Hartmannsberger
Diana
D
Department of Otorhinolaryngology, Head and Neck Surgery, Grosshadern Medical Center, Ludwig-Maximilians-University of Munich, Marchioninistr. 15, 81377 Munich, Germany.
Mack
Brigitte
B
Eggert
Carola
C
Denzel
Sabine
S
Stepp
Herbert
H
Betz
Christian S
CS
Gires
Olivier
O
D017209:Apoptosis; D002460:Cell Line; D049109:Cell Proliferation; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000502:physiology*; D008970:Molecular Weight; D010427:Pentose Phosphate Pathway; D012333:RNA, Messenger / Q000032:analysis; D034741:RNA, Small Interfering / Q000235:genetics; D014174:Transketolase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*
D036341:Intercellular Signaling Peptides and Proteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C505431:TKTL1 protein, human; D014174:Transketolase