Radiation-induced oesophagitis in lung cancer patients. Is susceptibility for neutropenia a risk factor?

BACKGROUND: Radiation-induced oesophagitis is a major side effect of concurrent chemotherapy and radiotherapy. A strong association between neutropenia and oesophagitis was previously shown, but external validation and further elucidation of the possible mechanisms are lacking. METHODS AND PATIENTS: A total of 119 patients were included at two institutions. The concurrent group comprised 34 SCLC patients treated with concurrent carboplatin and etoposide, and concurrent chest irradiation, and 36 NSCLC patients with concurrent cisplatin and etoposide, and concurrent radiotherapy, while the sequential group comprised 49 NSCLC patients received sequential cisplatin and gemcitabine, and radiotherapy. RESULTS: Severe neutropenia was very frequent during concurrent chemoradiation (grade: 4 41.4%) and during induction chemotherapy in sequentially treated patients (grade 4: 30.6%), but not during radiotherapy (only 4% grade 1). In the concurrent group, the odds ratios of grade 3 oesophagitis vs. neutropenia were the following: grade 2 vs. grade 0/1: 5.60 (95% CI 1.55-20.26), p = 0.009; grade 3 vs. grade 0/1: 10.40 (95% CI 3.19-33.95); p = 0.0001; grade 4 vs. grade 0/1: 12.60 (95% CI 4.36-36.43); p < 0.00001. There was no correlation between the occurrence of neutropenia during induction chemotherapy and acute oesophagitis during or after radiotherapy alone. In the univariate analysis, total radiation dose (p < 0.001), overall treatment time of radiotherapy (p < 0.001), mean oesophageal dose (p = 0.038) and neutropenia (p < 0.001) were significantly associated with the development of oesophagitis. In a multivariate analysis, only neutropenia remained significant (p = 0.023). CONCLUSION: We confirm that neutropenia is independently correlated with oesophagitis in concurrent chemoradiation, but that the susceptibility for chemotherapy-induced neutropenia is not associated with radiation-induced oesophagitis. Further studies focusing on the underlying mechanisms are thus warranted.

Human Caco-2 cells transfected with c-Ha-Ras as a model for endocrine differentiation in the large intestine.

Endocrine cells occur in approximately 30% of all colorectal adenocarcinomas, and this feature appears to correlate with a relatively poor prognosis. To study the factors regulating endocrine differentiation in colorectal cancer, which may bear resemblance to the regulation of endocrine differentiation in normal intestinal mucosa, models in which differentiation can be manipulated are essential. However, endocrine features in colorectal cancer cell lines are scarce and are almost exclusively observed in xenografts, presumably as a result of differentiation induction by stromal components. We attempted to demonstrate endocrine differentiation in the colonic adenocarcinoma cell line Caco-2, which is frequently used as a model for enterocytic differentiation. In vitro endocrine tumor cells were not encountered. In vivo studies were cumbersome, because of the low take rate of Caco-2 cells. We did manage to establish nude mouse xenografts of Caco-2 cells by inoculating cells in collagen gel and by suppressing natural killer cell activity. In an attempt to induce a better take rate and to investigate the effect of Ras oncoprotein overexpression on endocrine differentiation, Caco-2 cells were transfected with a point-mutated c-Ha-Ras gene. The cell line Caco-2 EJ6, generated from these experiments, could be xenografted in nude mice with a high take rate, yielding a moderately well differentiated adenocarcinoma, morphologically identical to the tumors derived from untransfected Caco-2 cells. The xenografts displayed goblet cell, enterocytic, Paneth cell and endocrine differentiation. In vitro endocrine differentiation was observed neither under standard conditions nor with extracellular matrix components as differentiation inducers. We conclude that the Caco-2 cell line and its c-Ha-Ras transfected subline Caco-2 EJ6 in vivo display endocrine differentiation. Ras overexpression does not enhance endocrine differentiation. Due to its favorable growth properties in vivo, Caco-2 EJ6 is a suitable model for studies on endocrine differentiation in colorectal cancer.

Extracellular matrix components induce endocrine differentiation in vitro in NCI-H716 cells.

Endocrine cells occur in +/- 30% of colorectal adenocarcinomas. The significance of this phenomenon in terms of tumor behavior is still controversial. Endocrine differentiation in colorectal cancer cell lines is almost confined to tumor xenografts in vivo, suggesting that endocrine differentiation might be regulated by epithelial-stromal interactions. This hypothesis was studied in the cecal adenocarcinoma-derived cell line NCI-H716 by comparing the expression of chromogranin A protein and messenger RNA in vivo and in vitro and by attempts to induce differentiation in vitro. We found that chromogranin A expression, which was strongest in vivo, could be significantly enhanced in vitro by culturing tumor cells in the presence of native extracellular matrix, on fibroblast feeder layers, and in a defined medium with basic fibroblast growth factor. The results suggest that the extracellular matrix induces endocrine differentiation through factors (e.g., basic fibroblast-growth factor) that may be produced by stromal cells and after secretion bind to the extracellular matrix.

NCI-H716 cells as a model for endocrine differentiation in colorectal cancer.

In colonic neoplasms, endocrine differentiation is encountered not only in carcinoid tumors but also in adenocarcinomas, where endocrine cells may represent a distinct line of differentiation in the tumor. The significance of endocrine differentiation in colorectal cancer is not well established, partly because of the paucity of tumor cell lines which can serve as a model for studying endocrine differentiation. In this report we describe the properties of NCI-H716 cells, a cell line derived from a poorly differentiated adenocarcinoma of the caecum, under various in vitro conditions and as xenografts in athymic mice. Phenotypical properties were immunohistochemically assessed using a panel of differentiation related antibodies, and also by Northern blot analysis and by electron microscopy. Receptors for biogenic amines and peptide hormones were analyzed by ligand binding assay. These studies show that: 1. NCI-H716 cells can be undifferentiated, or show endocrine, mucin-producing or "amphicrine" properties. 2. Endocrine differentiation of NCI-H716 cells preferentially occurs in xenografts in athymic mice, which suggests that mesenchymal elements induce endocrine differentiation. 3. NCI-H716 cells express large amounts of high affinity receptors for gastrin, serotonin and somatostatin and these substances can regulate growth. Thus, NCI-H716 cells form a suitable model for the study of endocrine differentiation in intestinal epithelium and of auto- or paracrine growth regulation in intestinal neoplasia.

Colonic epithelium reactive monoclonal antibodies. Identification and immunohistochemical localization of the target epitopes.

We have produced a small library of colonic mucosa and colorectal carcinoma reactive monoclonal antibodies (MoAbs) by immunizations with extracts of human colon cancer tissue and a human colon cancer cell line. Hybridoma supernatants were tested on (normal and neoplastic) human tissues by immunoperoxidase methods to evaluate organ or tissue specificity. Initial biochemical characterization of the target antigens was performed by gelpermeation chromatography, Western blotting and competition assays. Based upon the immunoreactivity patterns and the characteristics of the antigen four groups of MoAbs could be distinguished. The first group concerns the antibodies PARLAM 3, 9 and 10. These antibodies react with an 87 kDa protein moiety in high molecular weight (2-5 x 10(6) Da) glycoproteins. In intestinal and colon mucosa these antibodies showed diffuse binding with goblet cells. In colon carcinoma decreased reactivity with these MoAbs was found. The second group consists of antibodies PARLAM 8, 12 and 13. These antibodies react with large (greater than 5 x 10(6) Da) glycoproteins, most likely with carbohydrate epitopes. By immunohistochemistry in normal colon mucosa the antibodies all show granular supranuclear reactivity with goblet cells. These antibodies show increased reactivity with colon adenomas and adenocarcinomas. A third group is formed by PARLAM 2, which also reacts with a large (greater than 5 x 10(6) Da) glycoprotein, showing a granular distribution in goblet cells. In colon carcinomas more extensive expression is found than in normal colonic mucosa. Finally, the fourth group consists of PARLAM 11, which also reacts with a large (greater than 5 x 10(6) Da) glycoprotein, located in the brush border of colonic columnar cells. These antibodies might be useful tools for the analysis of the expression of mucin related glycoproteins in normal, preneoplastic and neoplastic colon mucosa.