Early expression of the fractalkine receptor CX3CR1 in pancreatic carcinogenesis.

BACKGROUND: In pancreatic ductal adenocarcinoma (PDAC), fractalkine receptor CX3CR1 contributes to perineural invasion (PNI). We investigated whether CX3CR1 expression occurs early in PDAC and correlates with tumour features other than PNI. METHODS: We studied CX3CR1 and CX3CL1 expression by immunohistochemistry in 104 human PDAC and coexisting Pancreatic Intraepithelial Neoplasia (PanIN), and in PdxCre/LSL-Kras(G12D) mouse model of PDAC. CX3CR1 expression in vitro was studied by a spheroid model, and in vivo by syngenic mouse graft of tumour cells. RESULTS: In total, 56 (53.9%) PDAC expressed CX3CR1, 70 (67.3%) CX3CL1, and 45 (43.3%) both. CX3CR1 expression was independently associated with tumour glandular differentiation (P=0.005) and PNI (P=0.01). Pancreatic Intraepithelial Neoplasias were more frequently CX3CR1+ (80.3%, P<0.001) and CX3CL1+ (86.8%, P=0.002) than matched cancers. The survival of PDAC patients was better in those with CX3CR1+ tumour (P=0.05). Mouse PanINs were also CX3CR1(+) and -CL1(+). In vitro, cytokines significantly increased CX3CL1 but not CX3CR1 expression. Differently, CX3CR1 was upregulated in tumour spheroids, and in vivo only in well-differentiated tumours. CONCLUSION: Tumour differentiation, rather than inflammatory signalling, modulates CX3CR1 expression in PanINs and PDAC. CX3CR1 expression pattern suggests its early involvement in PDAC progression, outlining a potential target for interfering with the PanIN transition to invasive cancer.

Focal extra-axial hemorrahagic mass with subdural hemorrhage secondare to extramedullary hematopoiesis in idiopathic myelodysplastic sindrome.

Idiopathic myelodysplastic syndrome is a disease characterized by a clonal stem cell disorder in which megacaryocitic and granulocytic lineages are mainly involved; extramedullary myeloid metaplasia is due to abnormal location of myeloid tissue in other organs than bone marrow. Rarely the central nervous system is involved. When it happens, it is typical to find masses around the brain and pachymeningeal thickening, but it is very rare to find it associated with subdural haemorrhage, as in the case we describe in the present article. Considering our case and the literature we can suggest that radiological images associated with the clinical history of the patient suggestive for extramedullary hematopoiesis can be sufficient for a correct diagnosis and for a radiotherapy treatment, demanding surgery in the case of diagnostic doubts, massive hemorrahages or neurological decifits caused by the focal lesions.

Myxoid leiomyosarcoma of the left atrium: a rare malignancy of the heart and its comparison with atrial myxoma.

Primary tumours of the heart are rare. The majority of these tumours are benign, with myxomas located in the left atrium being the most common form. Almost all malignant tumours are sarcomas and occur preferentially in the right side of the heart. An exception to this rule is leiomyosarcoma, a rare form of primary cardiac sarcoma that occurs predominantly in the left atrium, as does cardiac myxoma. The case of a 53-year-old woman who presented with symptoms of mitral valve stenosis and pulmonary hypertension is reported. Cardiac catheterization, angiography and echocardiography revealed a left atrial mass that was interpreted as atrial myxoma. At the time of operation, the myxoid appearance of the tumour mass further supported this assumption. The tumour, including a wide rim of atrial septum, was removed with cautery. Histopathological examination unexpectedly showed that the tumour was not an atrial myxoma but rather a myxoid variant of a primary leiomyosarcoma. Immunohistochemistry and electron microscopy confirmed the diagnosis. Local radiotherapy was considered but deemed contraindicated in view of the longstanding pulmonary hypertension. Two months after excision, a repeat echocardiogram indicated recurrence of tumour in the left atrium, and the patient died a few days later. The preferential left atrial location and the frequently myxoid appearance of primary leiomyosarcomas of the heart make it particularly difficult to differentiate them preoperatively from atrial myxomas. The authors recommend resection of all atrial myxoid tumours with a wide (at least 1 cm) margin, combined with intraoperative frozen section diagnosis, because complete surgical resection appears to correlate with prolonged survival in the few reported cases of atrial leiomyosarcomas. In cases of incomplete initial resection or local recurrence in the absence of metastatic disease, heart transplantation may be a valid option in appropriately selected patients.

p21/WAF1 cyclin-kinase inhibitor expression in non-Hodgkin's lymphomas: a potential marker of p53 tumor-suppressor gene function.

p21WAF1 (wild-type p53-activated fragment 1) is involved in the control of mammalian cell cycle through the binding and inhibition of cyclin-dependent kinases (Cdk). Because the product of WAF1 gene is a potent downstream effector of the p53 tumor-suppressor gene function, its pattern of cellular expression might correlate with nuclear accumulation of p53-encoded protein and/or p53 gene mutations occurring in malignant lymphomas. To investigate this issue, we analyzed immunohistochemically the expression of p53 and p21WAF1 proteins in tissue involved by non-Hodgkin's lymphomas (NHLs;253 cases) of various histologic types. In a proportion of them (80 cases), we also investigated the possible presence of p53 gene mutations using single-strand conformation polymorphism analysis and direct DNA sequencing. The absence of both p21WAF1 and p53 proteins was observed in 147 of 217 cases (67.7%) among CD30-NHL and in only 8 of 36 (22.2%) CD30+cases, which were mostly anaplastic large-cell lymphomas. A consistent number (> 10%) of p21WAF1-expressing cells was shown in 48 of 253 (18.9%) NHL cases, with a higher incidence in CD30+cases (25/36 [69.4%]), which mostly (21/36) coexpressed p53. These latter cases were characterized by a germline configuration of the p53 gene. In 50 of 253 NHL samples (19.7%), 47 of which (21.6%) belong to the CD30-group, neoplastic cells were p53+/p21-. In all of these cases, the p53+cells accounted for more than 50% of neoplastic cells, up to 100%. Point mutations of p53 gene were solely observed in all investigated cases with this latter phenotype. Our findings strongly suggest that the combined immunohistochemical evaluation of p53 and p21WAF1 is a valuable means of assessing the functional status of the p53 tumor-suppressor gene product in NHL with potential application in the monitorage and prognostication of individual cases.

Quantitative study of ductal breast cancer progression. A progression index (P.I.) for premalignant lesions and in situ carcinoma.

The diagnostic subjective assessment of ductal premalignant proliferative lesions and in situ carcinoma of the breast produces unsatisfactory results. Since the phenotypical cell changes in tumour progression toward infiltrating cancer constitute a continuum, a grading on a continuous scale of values produces a more reliable and reproducible characterization. The diagnostic assessment for any individual patient may be expressed by a progression index (P.I.): its numerical values are based on the cellular changes measured in the individual cases. In this study, the progression index is based on two morphometric features, nuclear size and nucleolar area. In addition, the method presented may produce a ratio, stating the relative likelihood that each case represents one of the conventional diagnostic categories. Such a likelihood ratio may be obtained from the bivariate distribution of nuclear size and nucleolar area for the conventional diagnostic categories.

Quantitative study of ductal breast cancer progression. Morphometric evaluation of phenotypical changes occurring in benign and preinvasive epithelial lesions.

Fifty-nine cases of Breast Epithelial Proliferative Lesions (BEPL) and Ductal Carcinoma in Situ (DCIS), were studied by image analysis, to evaluate the nuclear changes occurring in the conventional diagnostic categories of ductal hyperplasia, atypical ductal hyperplasia and DCIS with quantitative methods. Diagnosis reproducibility is the main practical problem of these breast lesions. In fact, with subjective methods, the reproducibility appears to be very low and precarious especially for clinical demands. The objective, quantitative evaluation of cell phenotypical changes should be the method for both practical diagnostic problems and study of ductal cancer progression. The distribution pattern of the data in the feature, obtained with quantitative analysis, strongly suggests a continuum of changes, indicating an evolutionary process of Breast Ductal Carcinoma (BDC) progression in its preinvasive stage. Each observed case may be characterised by its own cellular, objective alterations and a progressive trend toward BDC can be stated. Since the actual changes of the proliferative phenotypes can be measured, and the values are reproducible, karyometric measurement may allow an objective grading of individual cases.

Regulation and localization of lymphocyte production in the bone marrow.

The homeostatic mechanisms which control B lymphocyte renewal in the bone marrow are unknown. Mouse bone marrow produces many small lymphocytes which develop surface IgM and other B lymphocyte properties. Putative precursors show cytoplasmic mu chains but earlier progenitors have been characterized. Some marrow small lymphocytes are long-lived recirculating B and T cells. [3H]Thymidine and IgM labelling in femoral marrow sections suggest that recirculating lymphocytes migrate mainly through the marrow periphery while indigenous lymphocytes may be formed peripherally and migrate centrally as they mature. Thus, the localization of lymphocytes appears to be non-random. The effects of possible regulatory factors on bone marrow small lymphocytes production have been examined by [3H]thymidine labelling and radioautography. Administration of anti-IgM antibodies in vivo eliminates all B lymphocytes but the marrow lymphocyte production rate remains unchanged. After sublethal X-irradiation the marrow shows an over-shoot B lymphocyte production, while the lymphocyte numbers in shielded marrow remain stable. In neonatally thymectomized or congenitally athymic mice marrow lymphocyte production is unaffected. Studies in germ-free and antigen-stimulated mice reveal a basal level of marrow lymphocyte production, normally stimulated non-specifically by environmental factors. Thus, marrow lymphocyte production appears to be basically independent of feedback control from the peripheral B lymphocyte pool or of specific humoral factors, but fluctuates widely after perturbation or when amplified by exogenous stimuli. These findings suggest the importance of microenvironmental factors, as yet undefined, in the regulation of bone marrow lymphocytes.