Stephanie S Tseng-Rogenski1, Yasushi Hamaya1, Daniel Y Choi1, John M Carethers2. 1. Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan. 2. Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan. Electronic address: jcarethe@umich.edu.
Abstract
BACKGROUND & AIMS: Elevated microsatellite alterations at selected tetranucleotide repeats (EMAST) is the most common DNA mismatch repair defect in colorectal cancers, observed in approximately 60% of specimens. This acquired genotype correlates with metastasis and poor outcomes for patients, and is associated with intra-epithelial inflammation and heterogeneous nuclear levels of the mismatch repair protein hMSH3. Inflammation and accompanying oxidative stress can cause hMSH3 to change its intracellular location, but little is known about the source of oxidative stress in cancer cells. We investigated whether cytokines mediate this process. METHODS: We analyzed levels of interleukin 6 (IL6) and its receptor (IL6R) in human colon and lung cancer cell lines by flow cytometry and enzyme-linked immunosorbent assay; proteins were localized by immunofluorescence and immunoblot analyses. IL6 signaling was blocked with antibodies against IL6, soluble glycoprotein 130 Fc fragments, and the signal transducers and activators of transcription 3 inhibitor NSC74859; a constitutively active form of STAT3 was expressed in colon and lung cancer cell lines to replicate IL6R signaling. EMAST was detected by DNA fragment analysis. Immunohistochemistry was used to examine levels of IL6 in 20 colorectal tumor and adjacent nontumor tissues. RESULTS: Incubation of colon and lung cancer cell lines with IL6, but not other cytokines, caused hMSH3, but no other mismatch repair proteins, to move from the nucleus to the cytosol after generation of oxidative stress; inhibition of IL6 signaling prevented this shift. Expression of constitutively active STAT3 also caused hMSH3 to translocate from the nucleus to the cytoplasm in cancer cell lines. Incubation of cells with IL6 led to tetranucleotide frameshifts, the signature for EMAST. EMAST-positive colorectal tumors had significantly higher levels of IL6 than EMAST-negative tumors. CONCLUSIONS: IL6 signaling disrupts the nuclear localization of hMSH3 and DNA repair, leading to EMAST in cancer cell lines. Inflammatory cytokines might therefore promote genetic alterations in human cancer cells.
BACKGROUND & AIMS: Elevated microsatellite alterations at selected tetranucleotide repeats (EMAST) is the most common DNA mismatch repair defect in colorectal cancers, observed in approximately 60% of specimens. This acquired genotype correlates with metastasis and poor outcomes for patients, and is associated with intra-epithelial inflammation and heterogeneous nuclear levels of the mismatch repair protein hMSH3. Inflammation and accompanying oxidative stress can cause hMSH3 to change its intracellular location, but little is known about the source of oxidative stress in cancer cells. We investigated whether cytokines mediate this process. METHODS: We analyzed levels of interleukin 6 (IL6) and its receptor (IL6R) in humancolon and lung cancer cell lines by flow cytometry and enzyme-linked immunosorbent assay; proteins were localized by immunofluorescence and immunoblot analyses. IL6 signaling was blocked with antibodies against IL6, soluble glycoprotein 130 Fc fragments, and the signal transducers and activators of transcription 3 inhibitor NSC74859; a constitutively active form of STAT3 was expressed in colon and lung cancer cell lines to replicate IL6R signaling. EMAST was detected by DNA fragment analysis. Immunohistochemistry was used to examine levels of IL6 in 20 colorectal tumor and adjacent nontumor tissues. RESULTS: Incubation of colon and lung cancer cell lines with IL6, but not other cytokines, caused hMSH3, but no other mismatch repair proteins, to move from the nucleus to the cytosol after generation of oxidative stress; inhibition of IL6 signaling prevented this shift. Expression of constitutively active STAT3 also caused hMSH3 to translocate from the nucleus to the cytoplasm in cancer cell lines. Incubation of cells with IL6 led to tetranucleotide frameshifts, the signature for EMAST. EMAST-positive colorectal tumors had significantly higher levels of IL6 than EMAST-negative tumors. CONCLUSIONS:IL6 signaling disrupts the nuclear localization of hMSH3 and DNA repair, leading to EMAST in cancer cell lines. Inflammatory cytokines might therefore promote genetic alterations in humancancer cells.
Authors: Heather Hampel; Wendy L Frankel; Edward Martin; Mark Arnold; Karamjit Khanduja; Philip Kuebler; Hidewaki Nakagawa; Kaisa Sotamaa; Thomas W Prior; Judith Westman; Jenny Panescu; Dan Fix; Janet Lockman; Ilene Comeras; Albert de la Chapelle Journal: N Engl J Med Date: 2005-05-05 Impact factor: 91.245
Authors: C R Boland; S N Thibodeau; S R Hamilton; D Sidransky; J R Eshleman; R W Burt; S J Meltzer; M A Rodriguez-Bigas; R Fodde; G N Ranzani; S Srivastava Journal: Cancer Res Date: 1998-11-15 Impact factor: 12.701
Authors: Gad Singer; Thore Kallinowski; Arndt Hartmann; Wolfgang Dietmaier; Peter J Wild; Peter Schraml; Guido Sauter; Michael J Mihatsch; Holger Moch Journal: Int J Cancer Date: 2004-11-20 Impact factor: 7.396
Authors: Peter C Heinrich; Iris Behrmann; Serge Haan; Heike M Hermanns; Gerhard Müller-Newen; Fred Schaper Journal: Biochem J Date: 2003-08-15 Impact factor: 3.857
Authors: John M Carethers; E Julieta Smith; Cynthia A Behling; Lanchinh Nguyen; Akihiro Tajima; Ryan T Doctolero; Betty L Cabrera; Ajay Goel; Christian A Arnold; Katsumi Miyai; C Richard Boland Journal: Gastroenterology Date: 2004-02 Impact factor: 22.682
Authors: J G Herman; A Umar; K Polyak; J R Graff; N Ahuja; J P Issa; S Markowitz; J K Willson; S R Hamilton; K W Kinzler; M F Kane; R D Kolodner; B Vogelstein; T A Kunkel; S B Baylin Journal: Proc Natl Acad Sci U S A Date: 1998-06-09 Impact factor: 11.205
Authors: James W F Catto; Abdel-Rahmene Azzouzi; Najla Amira; Ishtiaq Rehman; Kenneth M Feeley; Simon S Cross; Gaelle Fromont; Mathilde Sibony; Freddie C Hamdy; Oliver Cussenot; Mark Meuth Journal: Oncogene Date: 2003-11-27 Impact factor: 9.867
Authors: Stephanie S Tseng-Rogenski; Koji Munakata; Daniel Y Choi; Paul K Martin; Supal Mehta; Minoru Koi; Wei Zheng; Yang Zhang; John M Carethers Journal: Mol Cell Biol Date: 2020-06-15 Impact factor: 4.272