Publications by authors named "Pulivarthi H Rao"

Osteosarcoma, the most common pediatric bone tumor, is an aggressive heterogeneous malignancy defined by complex chromosomal aberrations. Overall survival rates remain at ~70%, but patients with chemoresistant or metastatic disease have extremely poor outcomes of <30%. A subgroup of tumors harbor amplification of chromosome 8q24.

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Acinic cell carcinoma (AcCC) is a morphologically distinctive salivary gland malignancy often associated with chromosome rearrangements leading to overexpression of the NR4A3 transcription factor. However, little is known about how NR4A3 contributes to AcCC biology. Detailed RNA-sequencing of 21 archived AcCC samples revealed fusion reads arising from recurrent t(4;9), t(9;12), t(8;9) or t(2;4) chromosomal translocations, which positioned highly active enhancers adjacent to the promoter of the gene or the closely related gene, resulting in their aberrant overexpression.

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Myeloid sarcoma (MS) is a neoplastic condition composed of immature myeloid cells involving an extramedullary site. We investigated underlying chromosomal and molecular alterations to assess potential molecular markers of prognosis and outcome in this rare pediatric disease. We conducted a retrospective review of clinicopathologic and cytogenetic data from 33 pediatric patients with MS (ages 1 month-18 years) at our institution over a 32 year period (1984-2016).

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The DNA helicase RECQL4 is known for its roles in DNA replication and repair. RECQL4 mutations cause several genetic disorders including Rothmund-Thomson syndrome (RTS), characterized by developmental defects and predisposition to osteosarcoma. Here we reprogrammed fibroblasts with a heterozygous RECQL4 mutation (c.

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Genetic mutations in TP53 contribute to multiple human cancers. Here we report the generation of a H1-p53(R248W/R248W) human embryonic stem cell line harboring a homozygous TP53 R248W mutation created by TALEN-mediated precise gene editing. The H1-p53(R248W/R248W) cell line maintains a normal karyotype, robust pluripotency gene expression, and the potential to differentiate to the three germ layers.

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The tumor suppressor gene TP53 is the most frequently mutated gene in human cancers. Many hot-spot mutations of TP53 confer novel functions not found in wild-type p53 and contribute to tumor development and progression. We report on the generation of a H1 human embryonic stem cell line carrying a homozygous TP53 R282W mutation using TALEN-mediated genome editing.

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Objectives: To develop and characterize in vitro salivary duct carcinoma as a surrogate for functional studies.

Materials And Methods: Cells were dispersed from tumor tissue fragments under sterile conditions in RPMI media. Disassociated cells were cultivated, immortalized with hTERT and propagated for more than 100 passages.

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Background: Genomic deletions, inversions, and other rearrangements known collectively as structural variations (SVs) are implicated in many human disorders. Technologies for sequencing DNA provide a potentially rich source of information in which to detect breakpoints of structural variations at base-pair resolution. However, accurate prediction of SVs remains challenging, and existing informatics tools predict rearrangements with significant rates of false positives or negatives.

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We report a rare translocation involving chromosomes 1q23 and 3p21 regions in a basaloid salivary carcinoma. Our case together with a previously reported instance of translocation involving chromosome 1q 21-24 region defines a specific chromosomal segment that may house a gene associated with the development of a subset of basaloid salivary tumors.

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We hereby report an unusual gastric tumor arising from the pyloric wall of the stomach in a 9-year-old child harboring the exceptionally rare translocation t(7;12) resulting in ACTB-GLI1 gene fusion. This tumor has been previously classified as pericytoma with t(7;12) and described in 6 patients, 2 of them children. We discuss the challenges in recognizing this rare entity and the importance of the molecular studies in establishing the correct diagnosis.

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Purpose: Adenoid cystic carcinoma (ACC) is an indolent salivary gland malignancy, characterized by t(6;9) translocations and MYB-NFIB gene fusions in approximately 50% of the tumors. The genetic alterations underlying t(6;9)-negative and t(6;9)-positive/MYB-NFIB fusion-negative ACC remain unknown. To uncover the genetic alterations in ACC lacking the canonical translocation and fusion transcript and identify new abnormalities in translocation positive tumors.

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Osteosarcomas (OSs) are characterized by high levels of genomic instability (GI). To gain insights into the GI and its contribution toward understanding the genetic basis of OS, we characterized 19 primary and 13 metastatic mouse tumors in a genetically engineered novel mouse model of OS by a combination of genomic techniques. Through the bone-specific deletion of the wild-type Trp53 locus or activation of a metastatic-promoting missense R172Hp53 allele, C57BL/6 mice developed either localized or metastatic OS.

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TP53, a well-known tumour suppressor gene that encodes p53, is frequently inactivated by mutation or deletion in most human tumours. A tremendous effort has been made to restore p53 activity in cancer therapies. However, no effective p53-based therapy has been successfully translated into clinical cancer treatment owing to the complexity of p53 signalling.

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Purpose: To investigate the molecular events associated with the activation of androgen receptor (AR) as a potential therapeutic target in patients with salivary duct carcinoma (SDC).

Experimental Design: Comprehensive molecular and expression analysis of the AR gene in 35 tumor specimens (20 males and 15 females) and cell lines derived from SDC using Western blotting and RT-PCR, FISH analysis, and DNA sequencing was conducted. In vitro and in vivo animal studies were also performed.

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Osteogenic sarcoma (OS) is a deadly skeletal malignancy whose cause is unknown. We report here a mouse model of OS based on conditional expression of the intracellular domain of Notch1 (NICD). Expression of the NICD in immature osteoblasts was sufficient to drive the formation of bone tumors, including OS, with complete penetrance.

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Separase, a protease encoded by the ESPL1 gene, cleaves the chromosomal cohesin during mitosis. Separase protein and transcripts are overexpressed in a wide range of human cancers. To investigate the physiological consequence of Separase overexpression in animals, we have generated a transgenic MMTV-Espl1 mouse model that overexpresses Separase protein in the mammary glands.

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Gene amplifications in the 17q chromosomal region are observed frequently in breast cancers. An integrative bioinformatics analysis of this region nominated the MAP3K3 gene as a potential therapeutic target in breast cancer. This gene encodes mitogen-activated protein kinase kinase kinase 3 (MAP3K3/MEKK3), which has not yet been reported to be associated with cancer-causing genetic aberrations.

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The molecular genetic alterations underlying the development and diversity of salivary gland carcinomas are largely unknown. To characterize these events, comparative genomic hybridization analysis was performed, using a single-nucleotide polymorphism microarray platform, of 60 fresh-frozen specimens that represent the main salivary carcinoma types: mucoepidermoid carcinoma (MEC), adenoid cystic carcinoma (ACC), and salivary duct carcinoma (SDC). The results were correlated with the clinicopathologic features and translocation statuses to characterize the genetic alterations.

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Background: Osteosarcoma (OS) is the most common malignant bone tumor in children and adolescents. The survival rate of patients with metastatic disease remains very dismal. Nevertheless, metastasis is a complex process and a single-level analysis is not likely to identify its key biological determinants.

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Background: Carcinoma ex pleomorphic adenoma (Ca ex-PA) is defined as a carcinoma arising from a primary (de novo) or recurrent benign pleomorphic adenoma (PA).

Methods: We present a parotid myoepithelial carcinoma ex pleomorphic adenoma in a 38-year-old man with a t(3;8)(p21;q13) as the only chromosomal alteration by cytogenetic and spectral karyotypic analysis (SKY).

Results: The finding of this translocation in a subset of PA and in the present case suggests a critical role for this event in the malignant transformation of PA.

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Objective: To investigate the molecular genetic heterogeneity associated with the t(6:9) in adenoid cystic carcinoma (ACC) and correlate the findings with patient clinical outcome.

Experimental Design: Multimolecular and genetic techniques complemented with massive pair-ended sequencing and single-nucleotide polymorphism array analyses were used on tumor specimens from 30 new and 52 previously analyzed fusion transcript-negative ACCs by reverse transcriptase PCR (RT-PCR). MYB mRNA expression level was determined by quantitative RT-PCR.

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The identification of specific cell surface markers that can be used to isolate liver progenitor cells will greatly facilitate experimentation to determine the role of these cells in liver regeneration and their potential for therapeutic transplantation. Previously, the cell surface marker, CD24, was observed to be expressed on undifferentiated bipotential mouse embryonic liver stem cells and 3,5-diethoxycarbonyl-1,4-dihydrocollidine-induced oval cells. Here, we describe the isolation and characterization of a rare, primary, nonhematopoietic, CD24+ progenitor cell population from normal, untreated mouse liver.

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