Kruppel-like factor 5 is not required for K-RasG12D lung tumorigenesis, but represses ABCG2 expression and is associated with better disease-specific survival.
K-RAS mutations are found in approximately 30% of lung cancers. The transcription factor Krüppel-like Factor 5 (KLF5) has been shown to mediate cellular transformation signaling events downstream of oncogenic RAS in other cancers, but a role for KLF5 in lung tumorigenesis has not been defined. We show here that knockdown of KLF5 expression significantly decreased anchorage-independent growth, but did not affect proliferation of human lung adenocarcinoma cells. Moreover, Klf5 is not required for lung tumor formation in an inducible oncogenic K-Ras(G12D) mouse model of lung tumorigenesis, and non-small cell lung cancer patients expressing high levels of KLF5 (21/258) have a significantly better disease-specific survival than those with intermediate to no KLF5 expression. Further, KLF5 knockdown in K-RAS-mutant human lung cancer cells resulted in a fivefold increase in ATP-binding cassette, subfamily G (WHITE), member 2 (ABCG2), an anthracycline drug transporter, which lead to significantly increased resistance to doxorubicin treatment, a chemotherapeutic agent clinically used to treat lung cancer. In summary, while KLF5 is not required for oncogenic mutant K-Ras-induced lung tumorigenesis, KLF5 regulation of ABCG2 expression may be important for chemotherapeutic resistance and patient survival.
Meyer
Sara E
SE
Division of Immunobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.
Hasenstein
Jason R
JR
Baktula
Avinash
A
Velu
Chinavenmani S
CS
Xu
Yan
Y
Wan
Huajing
H
Whitsett
Jeffrey A
JA
Gilks
C Blake
CB
Grimes
H Leighton
HL
D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism*; D000704:Analysis of Variance; D000818:Animals; D015153:Blotting, Western; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic / Q000235:genetics; D002478:Cells, Cultured; D047369:Chromatin Immunoprecipitation; D018572:Disease-Free Survival; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D051741:Kruppel-Like Transcription Factors / Q000235:genetics / Q000378:metabolism*; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D016283:Proto-Oncogene Proteins p21(ras); D020133:Reverse Transcriptase Polymerase Chain Reaction; D046888:Tissue Array Analysis; D018631:ras Proteins / Q000235:genetics / Q000378:metabolism*
C116614:ABCG2 protein, human; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; C492214:KLF5 protein, human; C117307:KRAS protein, human; D051741:Kruppel-Like Transcription Factors; D009363:Neoplasm Proteins; D011518:Proto-Oncogene Proteins; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins