Co-expression of M-CSF transcripts and protein, FMS (M-CSF receptor) transcripts and protein, and steroid receptor content in adenocarcinomas of the ovary

The Role of CSF-1 in Normal Physiology of Mammary Gland and Breast Cancer: An Update

Colony stimulating factor (CSF-1) and its receptor (CSF-1R, product of c-fms proto-oncogene) were initially implicated as essential for normal monocyte development as well as for trophoblastic implantation. However, studies have demonstrated that CSF-1 and CSF-1R have additional roles in mammary gland development during pregnancy and lactation. This apparent role for CSF-1/CSF-1R in normal mammary gland development is very intriguing because this receptor/ligand pair has also been found to be important in the biology of breast cancer in which abnormal expression of CSF-1 and its receptor correlates with tumor cell invasiveness and adverse clinical prognosis. Recent findings also implicate tumor-produced CSF-1 in promotion of bone metastasis in breast cancer, and a certain membrane-associated form of CSF-1 appears to induce immunity against tumors. This review aims to summarize recent findings on the role of CSF-1 and its receptor in normal and neoplastic mammary development that may elucidate potential relationships of growth factor–induced biological changes in the breast during pregnancy and tumor progression.

Biomarker discovery in ovarian cancer

Ovarian cancer is a leading cause of gynecologic cancer death among women. Tumors diagnosed early (in stage I) have a cure rate approaching 90%. However, because specific symptoms and screening tools are lacking, most ovarian cancers are very advanced when finally diagnosed. CA125 expression and pelvic ultrasonography are of limited efficacy in screening, and the search for new, complementary ovarian cancer biomarkers continues. New technology and research techniques have allowed the identification of over 100 possible tumor markers, many of which are still being evaluated for clinical relevance and several of which have entered clinical trials. Here, we review the methods of biomarker discovery, address the significance and functions of newly identified ovarian cancer tumor markers, and provide further insight into the future of ovarian cancer biomarkers.

Harnessing the tumour-derived cytokine, CSF-1, to co-stimulate T-cell growth and activation

Aberrant growth factor production is a prevalent mechanism in tumourigenesis. If T-cells responded positively to a cancer-derived cytokine, this might result in selective enhancement of function within the tumour microenvironment. Here, we have chosen colony-stimulating factor-1 (CSF-1) as a candidate to test this concept. CSF-1 is greatly overproduced in many cancers but has no direct effects upon T-lymphocytes, which do not express the c-fms-encoded CSF-1 receptor. To confer CSF-1-responsiveness, we have expressed the human c-fms gene in immortalized and primary T-cells. Addition of soluble CSF-1 resulted in synergistic enhancement of IL-2-driven T-cell proliferation. CSF-1 also co-stimulated the production of interferon (IFN)-gamma by activated T-cells. These effects required Y809 of the CSF-1R and activation of the Ras-MEK-MAP kinase cascade, but were independent of PI3K signalling. T-cells that express c-fms are also responsive to membrane-anchored CSF-1 (mCSF-1) which, unlike its soluble counterpart, could co-stimulate IL-2 production. CSF-1 promoted chemotaxis of c-fms-expressing primary human T-cells and greatly augmented proliferation mediated by a tumour-targeted chimeric antigen receptor, with preservation of tumour cytolytic activity. Taken together, these data establish that T-cells may be genetically modified to acquire responsiveness to CSF-1 and provide proof-of-principle for a novel strategy to enhance the effectiveness of adoptive T-cell immunotherapy.

Expression of CSF-1 and its receptor CSF-1R in non-hematopoietic neoplasms

CSF-1 and its receptor appear to be important in the physiology of several different neoplasms including those of the breast and female reproductive tract. Levels of CSF-1 and CSF-1R expression appear to correlate with tumor cell invasiveness and an adverse clinical prognosis and may be modulated by hormones involved in normal lactogenic differentiation. Also, it appears that CSF-1R activates several different signal transduction pathways but only some of these appear to have direct bearing on tumor cell phenotypes and the activation of pathways in specific cell types may depend on factors above and beyond the receptor itself.

Does [meso-1,2-bis(2,6-dichloro-4-hydroxyphenyl)ethylenediamine]- dichloro-platinum(II) act as an immune response modifier? Part III: Progressively growing MXT-M-3,2 breast cancer stimulates the proliferation of phagocytes in B6D2F1 mice

MXT-M-3,2 breast cancer implanted into female B6D2F1 mice accelerates the growth of an identical second tumor. This process is accompanied by a significant increase of the granulocyte and monocyte numbers in the blood and of the granulocyte and macrophage numbers in the spleen. A significant positive correlation of strong intensity was found between the tumor weight on the one hand and the number of the granulocytes and macrophages on the other hand. The tumor-dependent promotion of the myelopoiesis is explained with a secretion of hematopoietic growth factors, e.g. of the granulocyte-macrophage-stimulating growth factor (GM-CSF), by the breast cancer cells.

CSF-1 and its receptor in breast carcinomas and neoplasms of the female reproductive tract

The expression and function of CSF-1 and its receptor were studied in tumors of the human breast, ovary, and endometrium. CSF-1 and its receptor, initially implicated as essential to normal monocyte development and trophoblastic implantation, have been more recently shown to be expressed by carcinomas of the breast and other epithelia of the female reproductive tract where activation of the receptor by ligand produced either by the tumor cells or by stromal elements stimulates tumor cell invasion by a urokinase-dependent mechanism. Breast carcinomas express wild-type CSF-1 receptors (CSF-1R) at levels comparable to those observed in trophoblast and monocytes. Ovarian and endometrial carcinomas express significantly lower levels of wild-type, functional CSF-1Rs, while ovarian carcinomas also express unusual transcripts that diverge from the wild-type CSF-1R transcript in their 5' extracellular domain sequences. Tumor cell expression of CSF-1R is under the control of several steroid hormones (glucocorticoids and progestins) and the binding of several bHLH transcription factors, while tumor cell expression of CSF-1 appears to be regulated by other hormones, some of which are involved in normal lactogenic differentiation. In addition, tumor cells often produce CSF-1 at such high levels that the cytokine spills into the extracellular fluid and circulation. Measurements of circulating levels of CSF-1 have proved useful in patients with ovarian, endometrial, and breast carcinoma both for disease detection and monitoring of response to therapy. CSF-1 and its receptor appear to be an important receptor/ligand pair in the biology of breast cancers and tumors of the female reproductive tract where they may regulate functions similar to those they control during macrophage activation and placental implantation.

Modulation of c-fms proto-oncogene in an ovarian carcinoma cell line by a hammerhead ribozyme

Co-expression of macrophage colony-stimulating factor (M-CSF) and its receptor (c-fms) is often found in ovarian epithelial carcinoma, suggesting the existence of autocrine regulation of cell growth by M-CSF. To block this autocrine loop, we have developed hammerhead ribozymes against c-fms mRNA. As target sites of the ribozyme, we chose the GUC sequence in codon 18 and codon 27 of c-fms mRNA. Two kinds of ribozymes were able to cleave an artificial c-fms RNA substrate in a cell-free system, although the ribozyme against codon 18 was much more efficient than that against codon 27. We next constructed an expression vector carrying a ribozyme sequence that targeted the GUC sequence in codon 18 of c-fms mRNA. It was introduced into TYK-nu cells that expressed M-CSF and its receptor. Its transfectant showed a reduced growth potential. The expression levels of c-fms protein and mRNA in the transfectant were clearly decreased with the expression of ribozyme RNA compared with that of an untransfected control or a transfectant with the vector without the ribozyme sequence. These results suggest that the ribozyme against GUC in codon 18 of c-fms mRNA is a promising tool for blocking the autocrine loop of M-CSF in ovarian epithelial carcinoma.