Nitric oxide generated by iNOS reduces deformability of Lewis lung carcinoma cells.
Previous studies have indicated that NO plays a crucial role in the metastasis of tumor cells and that tumor cells produce nitric oxide (NO) via inducible nitric oxide synthase (iNOS). Since the deformability of tumor cells is an important factor governing their metastatic potential, in this study we investigated the regulation of tumor cell deformability by NO. Lewis lung tumor cells (3LL cells) were also incubated with a cytokine mixture (IL-1 beta, IFN gamma, and TNF alpha). The nitrite/nitrate content of the supernatant was then measured by the Griess method, and iNOS expression was evaluated by RT-PCR in vitro. Nitrite/nitrate was produced in response to administration of the cytokine mixture, and iNOS mRNA was expressed in the cytokine-treated cells. The deformability of the 3LL cells was evaluated by measuring the peak pressure generated during their passage through a microfilter at a constant flow rate. Both the cytokine mixture and NO donor (NOC 18) significantly increased the filtration pressure, and the staining of the cells with rhodamine-phalloidin revealed assembly of F-actin in the cell membrane. In conclusion, NO plays a role in the decreased deformability of tumor cells, suggesting that NO is one of the factors that regulates metastasis.
Igawa
Satoshi
S
Program of Clinical Medicine, Department of Internal Medicine (Respiratory Disease and Collagen Disease), Graduate School of Medical Sciences, Kitasato University, Sagamihara, Kanagawa 228-8555, Japan.
Hayashi
Izumi
I
Tanaka
Naohiko
N
Hiruma
Hiromi
H
Majima
Masataka
M
Kawakami
Tadashi
T
Hirose
Minoru
M
Masuda
Noriyuki
N
Kobayashi
Hirosuke
H
D000818:Animals; D018827:Carcinoma, Lewis Lung / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor / Q000637:transplantation; D016207:Cytokines / Q000494:pharmacology; D004790:Enzyme Induction; D008175:Lung Neoplasms / Q000378:metabolism / Q000556:secondary*; D051379:Mice; D008810:Mice, Inbred C57BL; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D009368:Neoplasm Transplantation; D014411:Neoplastic Stem Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D009566:Nitrates / Q000032:analysis; D009569:Nitric Oxide / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000235:genetics / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II; D009573:Nitrites / Q000032:analysis; D012333:RNA, Messenger / Q000096:biosynthesis; D012334:RNA, Neoplasm / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012212:Rheology
D016207:Cytokines; D009363:Neoplasm Proteins; D009566:Nitrates; D009573:Nitrites; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse