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Biomedical subjects

C Sreekantaiah

Publications and source records attributed to C Sreekantaiah.

At least 19 recordsLinked to original sources
PubMed2001

Secondary acute myelogenous leukemia and myelodysplasia without abnormalities of chromosome 11q23 following treatment of acute leukemia with topoisomerase II-based chemotherapy.

Therapy-related MDS and AML are complications of intensive chemotherapy regimens. Traditionally, patients exposed to topoisomerase II inhibitors are reported to develop secondary AML with abnormalities of chromosome 11q23. We evaluated the long-term hematologic toxicity of topoisomerase II-intensive high-dose mitoxantrone-based chemotherapy in 163 newly diagnosed acute leukemia patients treated over an 8 year period. Nine (5.5%) patients developed new cytogenetic abnormalities. Four patients developed MDS with progression to AML, three patients developed new abnormalities at the time of relapse, and three patients (including one of the former patients) had changes that were not associated with hematologic disease. The abnormalities most frequently involved chromosomes 7q, 20q, 1q, and 13q. Despite the use of topoisomerase II-intensive treatment, no patient developed an abnormality involving chromosome 11q23. Spontaneous resolution of some changes and prolonged persistence of others in the absence of hematologic disease indicates that some cytogenetic changes are not sufficient to promote leukemogenesis.

Acute Disease↗
PubMed1999

Characterization of a complex chromosomal rearrangement in a patient with a typical catlike cry and no other clinical findings of cri-du-chat syndrome.

We report on the clinical, cytogenetic, and molecular cytogenetic findings in a 4-year-old girl who was evaluated for developmental delay and a catlike cry from birth. No other findings of cri-du-chat syndrome were present. Karyotype analysis demonstrated a de novo deletion and inverted duplication of the 5p region. The abnormality was confirmed and further defined by detailed FISH analysis using cosmid and lambda phage clones previously mapped to distinct regions of 5p. The analyses documented deletion of 5p15.3-->pter and an inverted duplication of 5p14-->5p15.3. The deleted segment on 5p contains the region implicated in the isolated catlike cry feature of the cri-du-chat syndrome, confirming that the genes involved in the catlike cry map to the distal end of 5p. Except for the catlike cry and possibly the developmental delay that may be due to the deletion of 5p, the duplication of 5p14-->5p15.3 in this patient did not present with additional anomalies. This study further demonstrates the usefulness of the molecular cytogenetic approach for characterizing complex chromosome rearrangements. Such analyses of patients with an isolated catlike cry can avoid an incorrect diagnosis of the cri-du-chat syndrome, which is associated with a more severe prognosis.

Child, Preschool↗
PubMed1999

Cytogenetic and molecular characterization of a malignant mixed müllerian tumor of the uterus with a t(8;22)(q24.1;q12).

We report the cytogenetic and molecular findings in a malignant mixed Müllerian tumor of the uterus in a 65-year-old woman. Karyotypic analysis revealed a t(8;22)(q24.1;q12) as the sole abnormality in all 20 cells analyzed. Southern blot analysis of two positional candidate genes, MYC at 8q24, and EWS at 22q12, showed no genomic rearrangement. The finding of the t(8;22) as the only abnormality may be of etiologic significance.

Adenocarcinoma↗
PubMed1999

Biphenotypic (mixed myeloid/T-cell) extramedullary myeloid cell tumor.

A 32-year-old male with a 4-year history of chronic myelogenous leukemia (CML) in chronic phase for 4 years, then myeloid blast crisis for 7 months, developed diffuse bulky lymphadenopathy in association with a white blood count (WBC) of 17,100/mm3 with 70% blasts. Biopsy of a cervical lymph node revealed a blastic extramedullary myeloid cell tumor, which showed a biphenotypic (mixed myeloid/T-cell) immunophenotype. Chromosomal analysis revealed karyotypic features of both myeloid and lymphoid lineages. Although extramedullary myeloid cell tumor (EMT, granulocytic sarcoma, chloroma) is well known to occur in chronic myelogenous leukemia (CML), to our knowledge this is the first description of evolution of CML into a biphenotypic EMT.

Adult↗
PubMed1998

Isochromosomes 7q and 17q in Wilms tumor.

We report the cytogenetic findings in a Wilms tumor from a 4-year-old boy. Karyotypic analysis revealed isochromosomes of 7q and 17q as coexisting clonal aberrations. The finding is notable in view of recent reports of i(7q) as a nonrandom event in Wilms tumor and the emerging evidence for genetic heterogeneity in this tumor.

Child, Preschool↗
PubMed1998

The cytogenetic and molecular characterization of benign and malignant soft tissue tumors.

Cytogenetic analyses of benign and malignant soft tissue tumors have led to the description of recurrent, specific, and even pathognomonic chromosomal translocations and/or other rearrangements in most types of soft tissue tumors. The consistent karyotypic rearrangements have provided critical diagnostic information in this group of neoplasms that often presents significant diagnostic challenges to the clinician and the pathologist. These findings have also been instrumental in the characterization of the abnormalities at the molecular level. Novel genes have been isolated from the translocation junctions and the mechanisms of their deregulation identified. This has increased our understanding of the histogenesis of these tumors, paved the way for the molecular diagnosis of many sarcomas, aided in directing therapy, and also provided important prognostic information.

Chromosome Aberrations↗
PubMed1997

Congenital pulmonary myofibroblastic tumor: a case report with cytogenetic analysis and review of the literature.

We report a case of congenital pulmonary myofibroblastic tumor, and review prior reports of this rare neoplasm to demonstrate its clinically benign behavior despite histologic features previously interpreted as sarcoma. The patient, a female neonate, presented with severe respiratory distress after cesarean section delivery. A large radio-opaque mass was detected in the right hemithorax and resected by right bilobectomy. The tumor mass, confined to the lung, was composed of interlacing fascicles of plump spindle cells showing myofibroblastic differentiation and complex cytogenetic abnormalities. Though sarcomatous in appearance, with highly cellular areas and numerous mitoses, there has been neither tumor recurrence nor metastases. The patient remains alive and well 1 year after surgery. Review of the few other reported cases confirms the uniformly benign behavior of this tumor.

Female↗
PubMed1994

Genetic changes in epithelial solid neoplasia.

Although chromosomal analysis of solid epithelial neoplasms has lagged behind that of hematopoietic, mesenchymal, and germ cell tumors, gradual accumulation of data over the past 5 years enables development of a general view. Thus, these tumors appear to be characterized by a set of nonrandom deletions the incidence of which varies in tumors of different histological types. Most tumors were studied at advanced stages; therefore, essentially no data are available on the cytogenetic characteristics of the earliest stages of tumorigenesis. In contrast to the status of cytogenetic data, a large body of information on deletions at the molecular level assayed by the loss of heterozygosity analysis has accumulated over the same period. These data have been less complete than the cytogenetic data, although in cases such as colorectal carcinoma, genetic changes from the earliest to the most advanced stages have been studied in detail providing a genetic view of progression. Equally important is the fact that deletion mapping studies by the loss of heterozygosity assay directly lead to isolation of a number of tumor suppressor genes. A comparison of the pattern of deletions identified by chromosomal and loss of heterozygosity analysis revealed, as expected, a concordance. Comparison of the patterns of chromosomal (and the underlying molecular) changes in tumors between major embryological cell types demonstrates fundamental differences in genetic mechanisms which lead to tumorigenesis.

Chromosome Aberrations↗
PubMed1994

Consistent chromosomal losses in head and neck squamous cell carcinoma cell lines.

Clonal chromosomal abnormalities were characterized in nine cell lines established from squamous cell carcinomas of the head and neck. Aneuploidy was a common feature; one cell line was near-diploid, three were near-triploid, four were near-tetraploid, and one cell line showed extensive variation in chromosome numbers. Consistent numerical abnormalities included loss of the sex chromosomes in six cell lines, losses of chromosomes 2 and 21 in six and five cell lines, respectively, and gain of chromosome 20 in five cell lines. Recurrent structural rearrangements included del(10)(q22-q26) (seven cell lines), i(5)(p10) (six cell lines), i(8)(q10) (six cell lines), add(19)(q13) (six cell lines), del(4)(q21-q31.3) (five cell lines), i(3)(q10) (four cell lines), del(12)(p11.1-p12) (four cell lines), and add (18)(q21-q23) (four cell lines). Other changes were noted in lower frequencies. Loss of specific regions on chromosomes 2, 3p, 4q, 5q, 8p, 10q, 12p, 18q, 19q, and 21 suggests that they may represent sites of putative tumor suppressor genes, loss of which may play a role in the pathogenesis of squamous cell carcinomas of the head and neck. Alternatively, gain of chromosomal region 3q, 5p, and 8q due to isochromosome formation suggests that more than one mechanism is involved in malignant transformation. Cytogenetic evidence of gene amplification was found in two cell lines; as an hsr(11)(q13) in one and as dmins in the other. The clonal karyotypes of four cell lines were compared with those of their respective primary tumors. In all cell lines, clonal evolution had occurred, with loss of some rearrangements present in the primary tumors or the gain of additional abnormalities.

Aged↗
PubMed1994

Cytogenetic analysis of 11 squamous cell carcinomas of the head and neck.

We report clonal chromosomal abnormalities in short-term cultures of 11 squamous cell carcinomas of the head and neck. Recurrent deletions were seen at 1p13 (four cases), 6q15q26 (three cases), 6q21q25 (two cases), 12p11.2 (three cases), and 3p13-p23 (three cases). Structural aberrations affecting chromosome 11 with different breakpoints were seen in 7 of 11 tumors. Cytogenetic evidence for gene amplification in the form of homogeneously staining region (hsr) was seen in three tumors (two at 11q13). The results of this study shows that the 1p13, 3p13-p23, 6q15-q26, 6q21-q25, and 12p11.2 were frequently deleted in squamous cell carcinomas of the head and neck.

Adult↗
PubMed1994

Chromosomal aberrations in soft tissue tumors. Relevance to diagnosis, classification, and molecular mechanisms.

In recent years, significant progress has been made in identifying characteristic chromosomal rearrangements associated with several solid tumor types, notably sarcomas, a relatively rare subset of human cancer. Most sarcomas analyzed have been found to be characterized by recurrent chromosome translocations that are specific to histological types. We have reviewed published reports of chromosomal aberrations in benign and malignant soft tissue tumors and found an incidence of specific translocations in these neoplasms that ranged from 20% to 93% within histological tumor types. Identification of recurrent chromosomal abnormalities in benign tumors has resulted in a reappraisal of the general concept that benign tumors have a normal (diploid) chromosome constitution. The variety of recurrent changes present in the different tumor types attests to the cytogenetic diversity inherent in these tumors. The chromosomal rearrangements in each of the tumor types were unique and did not correspond to cancer-associated aberrations known from other solid or hematopoietic malignancies. Cytogenetics thus provides an essential adjunct to diagnostic surgical pathology in the case of malignant soft tissue tumors, which often present substantial diagnostic challenges. In addition, it represents another approach to determine the histogenetic origin of some tumors and identifies sites of gene deregulation for molecular analysis. Indeed, recent molecular analyses of several sarcoma-associated translocations have identified novel genes and novel mechanisms of their dysregulation.

Chromosome Aberrations↗
PubMed1993

Chromosomal abnormalities in leiomyosarcomas.

Thirty-eight tumors from 30 patients diagnosed as leiomyosarcoma were cytogenetically assessed after short term culture. The specimens were obtained from the retroperitoneum, gastrointestinal tract, and extremities. Chromosomal abnormalities were present in 18 tumors from 13 patients; 15 tumors had clonal changes, whereas 3 tumors had numerous nonclonal changes. Ten tumors from 10 patients had normal karyotypes and no results were obtained in 10 other tumors from 7 patients. Of the tumors with clonal chromosomal aberrations, 4 had near-diploid (3 hypo- and one hyperdiploid) modes, 8 were polyploid, and 3 were bimodal. No specific karyotypic change appeared to characterize the leiomyosarcomas, although involvement of some chromosomes appeared more frequent than others. A comparison of our findings with those reported in the literature revealed certain consistent structural rearrangements involving chromosomes 1, 7, 10, 13, and 14 at bands 1p36, 1p32, 1p13, 1q32, 7p11.1-p21, 7q32, 10q22, 13q14, and 14p11, respectively. Other bands less frequently rearranged were 3p13-p22, 3q21, 4q13-q23, 6q15-q21, 7q11.2-q22, 12q13-q14, 17q12-q25, 19q13.3-q13.4, and 20q12-q13.1. Numerical changes included recurrent loss of chromosomes 4, 9, 14, 15, 16, 18, 21, and 22. Identification of the abnormalities of these chromosomes is important in that it may predict the existence of oncogenes, tumor suppressor genes, and/or growth factor genes at these sites. Subsequent molecular analysis might then lead to the identification of the genes involved and ultimately to a better understanding of the pathogenesis of leiomyosarcomas.

Adult↗
PubMed1992

Cytogenetic findings in liposarcoma correlate with histopathologic subtypes.

The cytogenetic findings in 31 liposarcomas from 26 patients are reported. Four other tumors did not grow. Three histologic types are represented in this analysis. The well-differentiated liposarcomas were characterized by telomeric associations, large marker chromosomes and ring chromosomes, and in some cases, double minutes. The pleomorphic liposarcomas contained very high clonal chromosomal numbers with near-tetraploid modes and numerous variable, often unidentifiable, chromosomal abnormalities. The myxoid liposarcomas were characterized primarily by a t(12;16)(q13;p11) as the sole abnormality or additional changes. These results indicate that cytogenetic findings may provide a new criterion, not only for establishing the diagnosis of liposarcoma, but also for differentiating confusing histologic types of liposarcoma and these lesions from other types of sarcomas.

Aged↗
PubMed1992

Clonal chromosomal abnormalities in desmoid tumors. Implications for histopathogenesis.

Desmoid tumors (aggressive fibromatosis) are regarded as lesions of uncertain histopathogenesis. Cytogenetic analyses of 26 desmoid tumor specimens from abdominal or extraabdominal sites of 22 patients with or without Gardner's syndrome (GS) showed clonal karyotypic abnormalities in 7 cases, random abnormalities in 14 cases, and striking telomeric fusion in 5 cases. Loss of chromosome Y, a reported feature of fibromatosis in penile and palmar locations, was detected as a clonal aberration in two patients. Additionally, involvement of 5q was observed in six patients, two of whom had GS. Clonal interstitial deletions of 5q were observed in three patients, one with and two without GS. These findings confirm a clonal and probable neoplastic origin for desmoid tumor and suggest that abnormalities of the Y chromosome and 5q may be important in the genesis of this neoplasm.

Adolescent↗
PubMed1992

Double minute chromatin bodies in carcinoma of the human cervix uteri.

In direct G-banded preparations of 150 cases of cervical cancer, double minutes (dmin) were observed in 43% (64 cancers) of the patients, including a case of carcinoma-in-situ (CIS). The incidence of dmin varied from 1 to over 20 per cell. The karyotypic findings in the tumors containing dmin did not reveal any similarities and the prognosis of the patients with dmin was significantly worse compared to those without dmin. The presence of dmin in cytogenetic preparations of primary tumors may indicate a role in the maintenance and/or progression of malignancy, particularly as dmin have been suggested to represent amplified genes.

Adult↗
PubMed1992

Cytogenetic findings in a malignant fibrous histiocytoma of the gallbladder.

We report the cytogenetic findings in a rare tumor, a malignant fibrous histiocytoma of the gallbladder. Four related clones, two near-diploid and two near-tetraploid, which appeared to have been formed by a doubling of the near-diploid clones, were present. Numerous structural and numerical abnormalities characterized the tumor. Structural rearrangements included reciprocal translocations, translocations of unidentified material onto chromosomes, and deletions. Chromosomes involved in the rearrangements included 1, 3, 10, 12, 14, 16, and 19. Numerical changes included trisomy of chromosomes 2, 8, 10, and 20. Double minute chromatin bodies ranging in number from 5 to several were present in over a third of the cells.

Adult↗
PubMed1992

Herpes simplex virus and human papillomavirus sites correlate with chromosomal breakpoints in human cervical carcinoma.

The distribution of 1,912 breakpoints observed in a series of 148 cervical cancers was analyzed. Fifty bands were shown to be nonrandomly involved in chromosome structural rearrangements. One hundred thirty-three breaks were noted in bands known to contain a human papillomavirus integration site, and 454 breaks were noted in bands containing a herpes simplex virus breakage site. We suggest that herpes simplex viruses and, possibly, papillomaviruses play an important role in the carcinogenesis and/or development of cytogenetic abnormalities in cervical cancers.

Chromosome Aberrations↗