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Maneesh Jain

Publications and source records attributed to Maneesh Jain.

14 recordsLinked to original sources
PubMed2007

Expression of TAG-72 in ovarian cancer and its correlation with tumor stage and patient prognosis.

Tumor associated glycoprotein-72 (TAG-72), a pancarcinoma antigen, was initially identified in cancer tissues by its immunoreactivity to a monoclonal antibody B72.3. In this study, we have analyzed the expression and localization profiles of TAG-72 in ovarian cancer tissue samples of different stages and histological subtypes by immunohistochemistry using a second generation high affinity monoclonal antibody CC49. We have also studied the expression of TAG-72 in ovarian cancer cell lines by confocal microscopy and immunoblot analyses. A correlation between TAG-72 expression and localization with patients' prognosis was also analyzed using Kaplan-Meier analysis. Eighty eight percent of the ovarian cancer tissue samples (n=43) showed immunoreactivity with CC49 antibody. The expression of TAG-72 in advanced stage cancer tissues (mean composite score=3.7) was significantly higher (p=0.035) compared to the early stage tumors (mean composite score=2.3). However, no significant correlation of TAG-72 was observed with histological tumor types. A marginal correlation of TAG-72 staining with patients' survival was observed. Interestingly, the membrane localization of TAG-72 in tumors was significantly (p=0.0082) associated to the poor clinical outcome, while cytoplasmic staining was correlated significantly to a better prognosis (p=0.0051). Immunoblot analysis demonstrated the expression of TAG-72 in three ovarian cancer cell lines (OVCAR3, SB247 and COV362.4). In conclusion, the tumor-specific expression of TAG-72 and its association with disease stage indicate its potential as a marker for effective disease management and targeted cancer therapy.

Antibodies, Neoplasm↗
PubMed2006

Aberrant expression of MUC4 in ovarian carcinoma: diagnostic significance alone and in combination with MUC1 and MUC16 (CA125).

Mucins are being implicated in diagnosis, prognosis, and as therapeutic targets due to their aberrant expression in a variety of carcinomas. Here, we have analyzed the expression of MUC4 and have compared its potential usefulness in early detection and prognosis of ovarian carcinoma alone and in combination with other mucin antigens, MUC1 and MUC16. Clinical significance of the differential mucin expression was evaluated by grouping the tumor samples in early (stage I and II) and advanced (stage III and IV) stage cases and histological subtypes (serous, mucinous, endometrioid and clear cell). Correlation of these mucins with patient's survival (n=63) was determined by Kaplan-Meier analysis in order to predict their prognostic value. MUC4 showed significant overexpression in tumor cases (P<0.0001) with highest incidence (92.0%) among all three mucins. A significant overexpression of MUC1 (P<0.018) and MUC16 (P<0.0001) was also observed in 83.0 and 79.0% of tumor samples, respectively. Notably, MUC4 expression was significantly higher (P</=0.004) compared to both MUC1 and MUC16 in early-stage ovarian tumor samples with 100% incidence. In advanced stage ovarian tumors, all the mucins displayed overall comparable expression, nonetheless, MUC4 had highest prevalence (88.0%) compared to MUC1 (84.0%) and MUC16 (81.0%). A combined panel of MUC4 with MUC16 detected 100% of the late-stage tumor cases without compromising the specificity. Among histological subtypes, only MUC4 displayed 100% (n=5) sensitivity in mucinous ovarian tumors, while MUC1 and MUC16 detected 40 and 20% cases, respectively. The expression of MUC4, however, did not significantly correlate with the survival of the ovarian cancer patient, while a significant correlation of MUC16 with poor prognosis was observed. In conclusion, our study demonstrates that MUC4 could be a potential candidate marker for early diagnosis of epithelial ovarian carcinoma and can be utilized in combination with MUC16 to achieve greater sensitivity for the detection of late-stage tumors.

Adenocarcinoma, Clear Cell↗
PubMed2006

Optimal genotype determination in highly multiplexed SNP data.

High-throughput genotyping technologies that enable large association studies are already available. Tools for genotype determination starting from raw signal intensities need to be automated, robust, and flexible to provide optimal genotype determination given the specific requirements of a study. The key metrics describing the performance of a custom genotyping study are assay conversion, call rate, and genotype accuracy. These three metrics can be traded off against each other. Using the highly multiplexed Molecular Inversion Probe technology as an example, we describe a methodology for identifying the optimal trade-off. The methodology comprises: a robust clustering algorithm and assessment of a large number of data filter sets. The clustering algorithm allows for automatic genotype determination. Many different sets of filters are then applied to the clustered data, and performance metrics resulting from each filter set are calculated. These performance metrics relate to the power of a study and provide a framework to choose the most suitable filter set to the particular study.

Algorithms↗
PubMed2005

Multiplexed variation scanning for 1,000 amplicons in hundreds of patients using mismatch repair detection (MRD) on tag arrays.

Identification of the genetic basis of common disease may require comprehensive sequence analysis of coding regions and regulatory elements in patients and controls to find genetic effects caused by rare or heterogeneous mutations. In this study, we demonstrate how mismatch repair detection on tag arrays can be applied in a case-control study. Mismatch repair detection allows >1,000 amplicons to be screened for variations in a single laboratory reaction. Variation scanning in 939 amplicons, mostly in coding regions within a linkage peak, was done for 372 patients and 404 controls. In total, >180 Mb of DNA was scanned. Several variants more prevalent in patients than in controls were identified. This study demonstrates an approach to the discovery of susceptibility genes for common disease: large-scale direct sequence comparison between patients and controls. We believe this approach can be scaled up to allow sequence comparison in the whole-genome coding regions among large sets of cases and controls at a reasonable cost in the near future.

Autistic Disorder↗
PubMed2005

Penetratin improves tumor retention of single-chain antibodies: a novel step toward optimization of radioimmunotherapy of solid tumors.

Single-chain Fv (scFv) antibody fragments exhibit improved pharmacokinetics and biodistribution compared with intact IgG. The tumor uptake of scFvs is rapid, and the serum half-life is shorter than IgG. However, scFvs exhibit lower net dose deposition in the tumor due to a shorter residence time that limits their use in radioimmunotherapy. To improve the tumor uptake and retention of scFvs, we investigated the utility of cell-penetrating peptides, penetratin and transactivator of transcription (TAT). Biodistribution studies were done in LS174T tumor-bearing mice with divalent scFv derived from anti-tumor-associated glycoprotein 72 monoclonal antibody (mAb) CC49. Penetratin increased the tumor retention of scFvs without affecting the peak dose accumulation. The percentage of doses retained in tumors at 24 hours post-administration with a control (no peptide), penetratin, and TAT were 27.25%, 79.84%, and 48.55%, respectively, of that accumulated at 8 hours postinjection. The tumor-to-blood ratios at 24 hours postadministration were 7.14, 19.53, and 16.48 with control, penetratin, and TAT treatment, respectively, whereas the pharmacokinetics were unaltered. Coinjection with TAT, however, resulted in increased uptake of the radioconjugate by the lungs. Autoradiography of the excised tumors indicated a more homogenous distribution of the radiolabeled scFv with both penetratin and TAT in comparison with the control treatment. Real-time whole-body imaging of the live animals confirmed improved tumor localization with penetratin without any increase in the uptake by normal tissues. In conclusion, a significant improvement in the tumor retention of sc(Fv)2 was achieved by administration of penetratin. Therefore, the combination of penetratin and scFvs has the potential of improving the utility of mAb-based radiopharmaceuticals.

Animals↗
PubMed2005

Engineering and characterization of a divalent single-chain Fv angiotensin II fusion construct of the monoclonal antibody CC49.

For the therapy of solid tumors, co-administration of angiotensin II (AngII) results in an increased uptake of drugs into the tumor interstitium. We have engineered a dimeric sc(Fv)(2)-AngII fusion construct that combines the superior kinetics of covalent dimeric scFvs [sc(Fv)(2)], recognizing the pancarcinoma tumor-associated antigen 72 (TAG-72), with the advantageous intrinsic activity of AngII. The binding characteristics of the fusion construct were unaltered by the addition of the AngII sequence [affinity constant K(A) 1.18 x 10(7) and 8.42 x 10(6) M(-1) for sc(Fv)(2) and sc(Fv)(2)-AngII, respectively]. The binding of the fusion construct to the angiotensin receptor (AT(1)) was similar to AngII, and the arterial contraction was 16 +/- 1% of the response observed with norepinephrine. In animal studies, the radiolabeled sc(Fv)(2)-AngII construct exhibited similar uptake and a more homogeneous distribution within the tumor as compared to sc(Fv)(2).

Angiotensin II↗
PubMed2005

The in vivo characteristics of genetically engineered divalent and tetravalent single-chain antibody constructs.

Engineered multivalent single-chain Fv (scFv) constructs have been demonstrated to exhibit rapid blood clearance and better tumor penetration. To understand the short plasma half-life of multivalent single-chain antibody fragments, the pharmacokinetic properties of covalent dimeric scFv [sc(Fv)2], noncovalent tetrameric scFv {[sc(Fv)2]2} and IgG of MAb CC49 were examined. The scFvs displayed an ability to form higher molecular aggregates in vivo. A specific proteolytic cleavage of the linker sequence of the covalent dimeric or a deterioration of the noncovalent association of the dimeric scFv into tetravalent scFv constructs was not observed. In conclusion, sc(Fv)2 and [sc(Fv)2]2 are stable in vivo and have significant potential for diagnostic and therapeutic applications.

Animals↗
PubMed2005

Highly multiplexed molecular inversion probe genotyping: over 10,000 targeted SNPs genotyped in a single tube assay.

Large-scale genetic studies are highly dependent on efficient and scalable multiplex SNP assays. In this study, we report the development of Molecular Inversion Probe technology with four-color, single array detection, applied to large-scale genotyping of up to 12,000 SNPs per reaction. While generating 38,429 SNP assays using this technology in a population of 30 trios from the Centre d'Etude Polymorphisme Humain family panel as part of the International HapMap project, we established SNP conversion rates of approximately 90% with concordance rates >99.6% and completeness levels >98% for assays multiplexed up to 12,000plex levels. Furthermore, these individual metrics can be "traded off" and, by sacrificing a small fraction of the conversion rate, the accuracy can be increased to very high levels. No loss of performance is seen when scaling from 6,000plex to 12,000plex assays, strongly validating the ability of the technology to suppress cross-reactivity at high multiplex levels. The results of this study demonstrate the suitability of this technology for comprehensive association studies that use targeted SNPs in indirect linkage disequilibrium studies or that directly screen for causative mutations.

Chromosome Inversion↗
PubMed2004

Pharmacokinetics and biodistribution of 177Lu-labeled multivalent single-chain Fv construct of the pancarcinoma monoclonal antibody CC49.

PURPOSE: Lutetium-177 (177Lu) is a radionuclide of interest for radioimmunoimaging (RII) and radioimmunotherapy (RIT) on account of its short half-life (161 h) and the ability to emit both beta and gamma radiation. Single-chain Fv (scFv) constructs have shown advancement in cancer diagnosis and therapy due to the pharmacokinetics advantage and seem to be intriguing tools in oncology. The objective of this study was to evaluate the pharmacokinetics and biodistribution characteristics of the 177Lu-labeled tetravalent scFv of CC49 MAb and intact CC49 IgG in vivo. METHODS: Conjugation and labeling conditions of multivalent scFv with 177Lu were optimized without affecting integrity and immunoreactivity. For this purpose, multivalent scFv constructs {dimer, sc(Fv)2; tetramer, [sc(Fv)2]2} of the MAb CC49 were expressed as secretory proteins in Pichia pastoris. The purified scFv constructs and IgG form of CC49 were conjugated with a bifunctional chelating agent, ITCB-DTPA, and labeled with 177Lu. The comparative biodistribution, blood clearance, and tumor-targeting characteristics of 177Lu-labeled tetravalent [sc(Fv)2]2 construct of CC49 MAb and intact CC49 IgG were investigated in the athymic mice bearing LS-174T xenografts. RESULTS: Approximately, 90% of 177Lu incorporation was achieved using ITCB-DTPA chelator, and the labeled immunoconjugates maintained integrity and immunoreactivity. Blood clearance studies demonstrated an alpha half-life (t1/2alpha) of 177Lu-labeled [sc(Fv)2]2 and IgG of CC49 at 4.40 and 9.50 min and a beta half-life (t1/2beta) at 375 and 2,193 min, respectively. At 8 h post administration, the percent of the injected dose accumulated/gram (%ID/g) of the LS-174T tumor was 6.4+/-1.3 and 8.9+/-0.6 for 177Lu-labeled [sc(Fv)2]2 and IgG of CC49, respectively, in the absence of L-lysine. The corresponding values were 8.0+/-0.6 and 8.4+/-1.2 in the presence of L-lysine. Renal accumulation of [sc(Fv)2]2 was significantly (p<0.005) reduced in the presence of L-lysine. CONCLUSION: The results of this study demonstrate that the ITCB-DTPA conjugation and 177Lu-labeling of scFvs are feasible without influencing the antibody characteristics. 177Lu-labeled [sc(Fv)2]2 showed faster clearance and equivalent tumor uptake at 8 h compared with its IgG form, with a markedly reduced renal uptake in the presence of L-lysine. Therefore, 177Lu-labeled [sc(Fv)2]2 may be a potential radiopharmaceutical for the treatment of cancer.

Animals↗
PubMed2004

Generation and characterization of anti-MUC4 monoclonal antibodies reactive with normal and cancer cells in humans.

We have previously cloned the full-length cDNA (approximately 28 Kb) and established the complete genomic organization (25 exons/introns over 100 kb) of the human MUC4 mucin. This large molecule is predicted to protrude over 2 microm above the cell surface, in which MUC4alpha is an extracellular mucin-type glycoprotein subunit and MUC4beta is the transmembrane subunit. Over two thirds of the encoded protein sequence consists of 16-amino-acid tandem repeats (TR), which are flanked by unique sequences. In this study we generated and characterized monoclonal antibodies (MAbs) directed against the TR region of MUC4. Mice were immunized with a KLH-conjugated MUC4 TR peptide, STGDTTPLPVTDTSSV. Several clones were purified by three rounds of limited dilutions and stable clones presenting a sustained antibody production were selected for subsequent characterization. Antibodies were tested for their reactivity and specificity to recognize the MUC4 peptide and further screened by enzyme-linked immunosorbent assay (ELISA) and Western blotting analyses. One of the MAbs (8G7) was strongly reactive against the MUC4 peptide and with native MUC4 from human tissues or pancreatic cancer cells in Western blotting, immunohistochemistry, and confocal analysis. Anti-MUC4 MAb may represent a powerful tool for the study of MUC4 function under normal and pathological conditions and for diagnosis of solid tumors including those in the breast, pancreas, lungs, and ovaries.

Animals↗
PubMed2003

Multiplexed genotyping with sequence-tagged molecular inversion probes.

We report on the development of molecular inversion probe (MIP) genotyping, an efficient technology for large-scale single nucleotide polymorphism (SNP) analysis. This technique uses MIPs to produce inverted sequences, which undergo a unimolecular rearrangement and are then amplified by PCR using common primers and analyzed using universal sequence tag DNA microarrays, resulting in highly specific genotyping. With this technology, multiplex analysis of more than 1,000 probes in a single tube can be done using standard laboratory equipment. Genotypes are generated with a high call rate (95%) and high accuracy (>99%) as determined by independent sequencing.

Cells, Cultured↗
PubMed2003

Genotyping African haplotypes in ATM using a co-spotted single-base extension assay.

Human genetic analysis, including population genetic studies, increasingly calls for cost-effective, high-throughput methods for the rapid screening of single nucleotide polymorphisms (SNPs) across many individuals. The modified single-base extension assay described here (arrayed SBE) is a highly accurate and robust method for SNP genotyping that can deliver genotypes at 3.5 cents each, following PCR. Specifically, amino-modified probe/target pairs were prehybridized, then co-spotted in a microarray format prior to enzymatic addition of allele-specific nucleotides. Probe/target identity was determined solely by its physical location on the array rather than by hybridization to a complementary target, resulting in a call rate of 99-100%. These innovations result in an inexpensive, accurate assay with exceptional signal-to-noise ratios, depending on the glass surface employed. Comparison of glass slides from three different manufacturers indicated that aldehyde-based Zyomyx slides provided superior performance for this assay. Arrayed SBE was applied to study the geographic distribution of three African-specific haplotypes in the human ATM gene. Four selectively neutral markers, which define the haplotypes H5, H6, and H7, were screened in a total of 415 individuals. Region-specific haplotype frequencies were consistent with patterns of human migration across and outside of Africa, suggesting a possible haplotype origin in East Africa. Arrayed SBE was a robust tool for this analysis that could be applied to any situation requiring the genotyping of a few SNPs in many individuals.

Africa, Eastern↗
PubMed2002

Pharmacokinetics and biodistribution of genetically engineered antibodies.

The engineering of monoclonal antibodies has created a new generation of pharmaceuticals with the desired pharmacokinetics and biodistribution properties. For radioimmunotherapy and radioscintigraphy, optimum tumor targeting can be achieved using engineered constructs that provide high antigen affinity and specificity, effective tumor penetration, circulation properties that allow high tumor uptake with acceptable doses to the normal tissues, and fast clearance allowing low background. Recent advances have made possible the development of antibodies with these properties.

Animals↗