title: Human breast cancer tissues contain abundant phosphatidylcholine(36∶1) with high stearoyl-CoA desaturase-1 expression.
abstract: Breast cancer is the leading cause of cancer and mortality in women worldwide. Recent studies have argued that there is a close relationship between lipid synthesis and cancer progression because some enzymes related to lipid synthesis are overexpressed in breast cancer tissues. However, lipid distribution in breast cancer tissues has not been investigated. We aimed to visualize phosphatidylcholines (PCs) and lysoPCs (LPCs) in human breast cancer tissues by performing matrix assisted laser desorption/ionization-imaging mass spectrometry (MALDI-IMS), which is a novel technique that enables the visualization of molecules comprehensively. Twenty-nine breast tissue samples were obtained during surgery and subjected to MALDI-IMS analysis. We evaluated the heterogeneity of the distribution of PCs and LPCs on the tissues. Three species [PC(32∶1), PC(34∶1), and PC(36∶1)] of PCs with 1 mono-unsaturated fatty acid chain and 1 saturated fatty acid chain (MUFA-PCs) and one [PC(34∶0)] of PCs with 2 saturated fatty acid chains (SFA-PC) were relatively localized in cancerous areas rather than the rest of the sections (named reference area). In addition, the LPCs did not show any biased distribution. The relative amounts of PC(36∶1) compared to PC(36∶0) and that of PC(36∶1) to LPC(18∶0) were significantly higher in the cancerous areas. The protein expression of stearoyl-CoA desaturase-1 (SCD1), which is a synthetic enzyme of MUFA, showed accumulation in the cancerous areas as observed by the results of immunohistochemical staining. The ratios were further analyzed considering the differences in expressions of the estrogen receptor (ER), human epidermal growth factor receptor 2 (HER2), and Ki67. The ratios of the signal intensity of PC(34:1) to that of PC(34:0) was higher in the lesions with positive ER expression [corrected]. The contribution of SCD1 and other enzymes to the formation of the observed phospholipid composition is discussed.
authors.affiliation: Department of Surgery I, Hamamatsu University School of Medicine, Hamamatsu, Japan.
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Ide
authors.forename: Michihiko
authors.initials: M
authors.lastname: Waki
authors.forename: Takahiro
authors.initials: T
authors.lastname: Hayasaka
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Nishio
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Morita
authors.forename: Hiroki
authors.initials: H
authors.lastname: Tanaka
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sasaki
authors.forename: Kei
authors.initials: K
authors.lastname: Koizumi
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Matsunuma
authors.forename: Yuko
authors.initials: Y
authors.lastname: Hosokawa
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ogura
authors.forename: Norihiko
authors.initials: N
authors.lastname: Shiiya
authors.forename: Mitsutoshi
authors.initials: M
authors.lastname: Setou
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000201:enzymology* / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D008875:Middle Aged; D010713:Phosphatidylcholines / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013230:Stearoyl-CoA Desaturase / Q000378:metabolism*; D055815:Young Adult
chemical_list: D010713:Phosphatidylcholines; C523776:SCD1 protein, human; D013230:Stearoyl-CoA Desaturase