Impaired cell motility in chronic myeloid leukemic granulocytes related to altered cytoskeletal pattern.

The bactericidal activity of polymorphonuclear leucocyte (PMNL) against infection stimulates cytoskeletal changes accompanied with alteration in adhesion and locomotion. Microfilaments, the motile apparatus is known to regulate these changes by polymerization of monomeric G-actin to fibrous F-actin. PMNL from chronic myeloid leukemia (CML) patients have been reported to be defective in locomotion in response to synthetic peptide, n-formyl-methionyl-leucyl-phenylalanine (fMLP) but the mechanism leading to defective locomotion and their spatial reorganization remains unclear. Therefore, in order to study the cause of defective motility of PMNL from CML patients the spatial distribution and reorganization of microfilaments and microtubules in response to fMLP have been examined by transmission electron (TEM) and scanning electron microscopy (SEM). Under SEM, the PMNL-CML surface appeared smoother with reduced ruffling resulting in rounding off cells with lesser polarized morphology. Unstimulated PMNL from normal as well as CML subjects showed shorter and fewer microtubules and evenly distributed microfilaments as compared to fMLP stimulated PMNL. It is proposed that the cause of defective locomotion was due to reduced surface activity as a consequence of altered cytoskeletal configuration. This phenomenon seems to be related to impaired functional appendages and as a whole led to the defective cell motility and hence reduced chemotaxis in PMNL from CML patients.

Cytokeratin expression in human fetal tongue and buccal mucosa.

Expression of cytokeratins (CK), a subset of intermediate filament (IF) proteins in epithelia, is developmentally regulated. CK expression may also change after malignant transformation. Our earlier studies on CK expression in human oral tumours and pre-cancerous lesions have shown specific changes in CK expression. We analysed CK expression in human tongue and buccal mucosa (BM) in fetuses in the embryonic age group of 16 to 27 weeks using biochemical and immunohistochemical techniques to find out whether there is any similarity in CK expression in human oral squamous cell carcinomas (SCC) and fetal oral tissues. CK 1, 8 and 18 were detected in a majority of samples using both techniques. Our earlier studies had shown aberrant expression of CK 1 and 18 in many of the oral SCC and leukoplakias. Studies by immunohistochemistry showed that these different CK antigens were expressed in different cell layers. CK 1(2) were present in the stratified epithelial layers whereas CK 8 and 18 were restricted to glandular epithelium. Till 27 weeks of gestation, both tongue and BM expressed CK 1, 8 and 18 along with CK 6 and 16. Thus, fetal tissues showed some similarities in CK pattern with their respective SCC.

Chromosome investigations & clinical outcome in patients with myelodysplastic syndromes.

A total of 25 patients with primary myelodysplastic syndrome (p-MDS) were cytogenetically investigated. The incidence of abnormal karyotypes was higher, detected in 88 per cent of the patients and the most frequent abnormality was a terminal deletion of chromosome 7 (45% of the patients with abnormal karyotypes) followed by an i (17q) (18%), +21(14%), -5/5q (9%), del (11) (q22) (9%). Cytogenetic analysis after therapy/after leukaemic transformation indicated either stable clones (2 patients) or emergence of new clones such as inv(5) (q32q36), del (17) (p13), +20, +22 (1 patient each). It is to be noted that of the 8 patients with leukaemic transformation, 5 had del (7q). The leukaemic transformation (32% of the patients) was not related to the percentage of abnormal karyotypes not to the percentage of blasts at the time of the MDS presentation. Chromosome instability was shown by 10 (45%) patients. Our data indicate that higher frequency of chromosomal aberrations with involvement of chromosome 7 may be the result of underlying disease.

DNA analysis of breast cancer by flow cytometry & correlation with other prognostic parameters.

Flow cytometric estimation of DNA content (ploidy and S-phase fraction--SpF) was done on breast cancer tissues from 171 patients. Twenty eight per cent of the tumours were diploid and 72 per cent were aneuploid. SpF was measurable in 82 DNA histograms; of these 22.4 per cent had SpF less than 10 per cent, 34.1 per cent had SpF between 10-20 and 43.5 per cent had SpF greater than 20 per cent. The mean SpF of the measurable histograms was 19.01 per cent with a range 1.78 to 45.19 per cent. A significant correlation between DNA ploidy and SpF was observed (P less than 0.01). Eighty nine per cent of diploid tumours had SpF less than 10 per cent and 73 per cent of aneuploid tumours had SpF greater than 20 per cent. A significant correlation was also found between ploidy and SpF and oestrogen receptor (ER) status of the tumours (P less than 0.05) and between SpF and progesterone receptor (PgR) status of the tumours (P less than 0.05), but not between ploidy and PgR status of the tumours. A significant direct correlation was observed between SpF and tumour grade (P less than 0.05), but not between ploidy and tumour grade. No correlation was observed between DNA ploidy and SpF and tumour type, tumour size, axillary lymph node involvement, age and menopausal status of the patients. Although the incidence of breast cancer is one-third of that reported in the Western countries, there is apparently no biological difference between the various parameters studied.

Cytogenetic studies in Hodgkin's disease.

Chromosome studies were carried out by G-banding technique on the bone marrow cells of 24 newly diagnosed, untreated Hodgkin's disease patients and 25 treated patients. Seven of these treated patients had also been studied at diagnosis. In the untreated group of patients, cytogenetic studies were carried out on stimulated peripheral blood lymphocytes in 11 patients and on skin fibroblasts in five. Of the 24 untreated patients, 14 showed normal diploid pattern, while 10 were seen with 8-30 per cent chromosomally aberrant cells in the bone marrow. The frequent anomalies were trisomy C/8 and trisomy 22 seen in 5 and 4 patients respectively. The cytogenetic picture of peripheral blood lymphocytes revealed normal diploid pattern in 7 patients; while 4 other patients showed abnormal clones with trisomy 21. The cultured skin fibroblasts represented normal diploid karyotypes. An altered karyotypic pattern was seen in the bone marrow of treated patients. In patients with abnormal karyotypes, the common anomalies were monosomy C, monosomy D/15 and trisomy 21. In patients which showed no involvement of the bone marrow by haematological parameters, chromosomally abnormal karyotypes were seen in the marrow. Thus, marrow involvement can be detected earlier cytogenetically.