CCL25-CCR9 interaction modulates ovarian cancer cell migration, metalloproteinase expression, and invasion.
BACKGROUND
Ovarian carcinoma (OvCa) is the most lethal gynecological malignancy among women and its poor prognosis is mainly due to metastasis. Chemokine receptor CCR9 is primarily expressed by a small subset of immune cells and its only natural ligand, CCL25, is largely expressed in the thymus, which involutes with age. Other than the thymus, CCL25 is expressed by the small bowel. Interactions between CCL25 and CCR9 have been implicated in leukocyte trafficking to the small bowel, a frequent metastatic site for OvCa cells. The current study shows OvCa tissue and cells significantly express CCR9, which interacts with CCL25 to support carcinoma cell migration and invasion.


METHODS
RT-PCR and flow cytometry techniques were used to quantify the expression CCR9 by OvCa cells. OvCa tissue microarrays (TMA) was used to confirm CCR9 expression in clinical samples. The Aperio ScanScope scanning system was used to quantify immunohistochemical staining. Cell invasion and migration assays were performed using cell migration and matrigel invasion chambers. Matrix metalloproteinase (MMP) mRNAs were quantified by RT-PCR and active MMPs were quantified by ELISA.


RESULTS
Our results show significantly (p<0.001) higher expression of CCR9 by mucinous adenocarcinoma, papillary serous carcinoma, and endometriod ovarian carcinoma cases, than compared to non-neoplastic ovarian tissue. Furthermore, CCR9 expression was significantly elevated in OvCa cell lines (OVCAR-3 and CAOV-3) in comparison to normal adult ovarian epithelial cell mRNA. OvCa cells showed higher migratory and invasive potential towards chemotactic gradients of CCL25, which was inhibited by anti-CCR9 antibodies. Expression of collagenases (MMP-1, -8, and -13), gelatinases (MMP-2 and -9), and stromelysins (MMP-3, -10, and -11) by OvCa cells were modulated by CCL25 in a CCR9-dependent fashion.


CONCLUSIONS
These results demonstrate both biological significance and clinical relevance of CCL25 and CCR9 interactions in OvCa cell metastasis.
Johnson
Erica L
EL
Department of Microbiology, Biochemistry, & Immunology, Morehouse School of Medicine, 720 Westview Drive SW, Atlanta, GA 30310-1495, USA.
Singh
Rajesh
R
Singh
Shailesh
S
Johnson-Holiday
Crystal M
CM
Grizzle
William E
WE
Partridge
Edward E
EE
Lillard
James W
JW
D017209:Apoptosis; D015153:Blotting, Western; D002465:Cell Movement; D049109:Cell Proliferation; D019742:Chemokines, CC / Q000235:genetics* / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D006801:Humans; D007124:Immunoenzyme Techniques; D045726:Metalloproteases / Q000235:genetics* / Q000378:metabolism; D009361:Neoplasm Invasiveness; D010051:Ovarian Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D011379:Prognosis; D012333:RNA, Messenger / Q000235:genetics; D054388:Receptors, CCR / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D046888:Tissue Array Analysis; D014407:Tumor Cells, Cultured
C119309:CC chemokine receptor 9; C108074:CCL25 protein, human; D019742:Chemokines, CC; D012333:RNA, Messenger; D054388:Receptors, CCR; D045726:Metalloproteases