Investigating monoclonal antibody against cytokeratin 19 tumor marker.

Reactivity of the monoclonal antibody with the tumor markers is known to be different between cultured cells in vitro and transplanted tumors in vivo. The monoclonal antibody should be investigated regarding its specific accumulation in tumor-bearing mice for immunodetection or immunotherapy. We studied the biodistribution of radiolabeled monoclonal anti-GD3 antibody (IgM) in normal mice and nude mice bearing human melanoma xenografts. Tissue-to-blood distribution ratios of the antibody in the liver, spleen and kidney increased with time in both normal and melanoma-transplanted mice, but no significant changes were observed in other normal tissues up to 5 days after injection. Specific accumulation of the monoclonal anti-GD3 antibody in the grafted human melanoma (HMV-II) was observed 4 and 5 days after injection. On the other hand, no specific accumulation of standard murine IgM in the tissue of HMV-II was observed in mice bearing the HMV-II xenograft 5 days after injection. Because the tissue-to-blood ratio of the distribution in the tissue of HMV-II became larger than that of other tissues 4 and 5 days after administration, 4 days after the administration of the monoclonal anti-GD3 antibody were required for immunoscintigraphy. Accumulation of the monoclonal anti-GD3 antibody in other human melanomas (HMV-I, HMY-1 and SK-MEL188) inoculated into mice was also observed 4 days after the antibody administration. The monoclonal anti-GD3 antibody used in this study would be useful in immunodetection or immunotherapy.

Quantitative Assay of Immunoglobulin Free Light Chains (FLC): Evaluation of Monoclonal Versus Polyclonal Antibody and Immunoturbidimetric Versus Immunonephelometric Detection Technology

Thymidine kinase 1 (TK1), an enzyme involved in the synthesis of precursors for DNA, and thus proliferation dependent, has been suggested as a good tumour marker. We have recently developed poly/monoclonal antibodies against TK1, which proved useful for diagnostics in both serum and immunohistochemistry of cancer patients. The anti-TK1 monoclonal antibodies (mAbs) 1D11 and 1E3 were characterized by Western blot, immunoprecipitation and flow cytometry. TK1 mAbs and Ki-67 mAb were then used for immunohistochemistry staining of tumour sections from 54 patients with ductal infiltrated breast carcinoma. Results showed the relative number of patients with positively stained tumours for TK1 (mAb 1D11) and for Ki-67 (mAb MIB-1) were 47 and 41%, respectively, significantly related (p=0.007). Combination of TK1 mAbs 1D11 and 1E3 increased this number to 56%, due to detection of a significantly higher number of patients with grade 2 tumours. Patients with stage II and grade 2 tumours showed significantly higher TK1 staining when compared to stage I and grade 1. Ki-67 staining was significantly higher in stage III and grade 3. The tumours only stained for TK1 represented higher stages and grades, while tumours staining only for Ki-67 were of lower stages and grades. Combining TK1 and Ki-67 increased the number of patients with positively stained tumours to 69%. In conclusion, TK1 is a reliable marker for identification of patients with grade 2 tumours. The highest number of patients with positively stained tumours were obtained when both TK1 and Ki-67 markers were used.

The use of tumour markers in clinical practice

NONINVASIVE DETECTION OF BLADDER CANCER WITH THE BTA STAT TEST

A 38-year-old man was admitted with persistent productive cough and right anterior chest pain. Chest X-ray showed two large masses connected with each other, one in the right lung field and the other in the anterior mediastinum. A tentative diagnosis of either lung abscess or bronchogenic carcinoma was initially made, because of elevated serum tumor markers (SLX and SCC) and persisting refractory inflammatory sings. However, open chest drainage revealed a few fine hairs and atheromatous materials within the masses, and the diagnosis of teratoma was made. We removed these masses, and investigated the reason for the elevation of tumor markers. Staining with SLX monoclonal antibody demonstrated that the pancreatic tissue in the masses contained SLX. Although this is the first reported case of teratoma producing tumor marker (SLX), it is highly possible that tumor markers may be elevated in the majority of patients with teratoma because of the genesis of this tumor.

Objective To evaluate whether the protein SP70 could be used as a serum biomarker for the diagnosis of non-small cell lung cancer （NSCLC）. Methods Polyclonal antibody was prepared by immunizing New Zealand rabbit with SPC-A1 cells.Sandwich ELISA was carried out by using newly-prepared polyclonal antibody（PcMb）coating assay plates，monoclonal antibody（McAb）NJ001 and HRP goat anti-mouse antibody as primary antibody and labeling antibody respectively.After optimizing the experiment conditions，serum from 175 lung cancer patients ［80 NSCLC adenocarcinoma，70 NSCLC squamous carcinoma and 25 small cell lung cancer（SCLC）］，25 benign lung disease（BLD）patients and 300 healthy controls （HC） were examined.CEA，NSE，CYFRA21-1 were measured by ECLIA for comparison. Results Positive rates of NSCLC adenocarcinoma，NSCLC squamous carcinoma，SCLC and BLD were 68.8%，51.4%，16.0% and 12.0% respectively，obviously higher than that of HC（7.3%）．NSCLC（adenocarcinoma，Squamous carcinoma） had significantly higher positive rate than SCLC（60.7% vs 16.0%，χ2=17.23，P<0.05）and BLD（60.7% vs 12.0%，χ2=20.41，P<0.05）.Among 68 NSCLC patients who had definite staging，positive rates at early stage（Ⅰ/Ⅱ，n=30） reached up to 76.7%.Meanwhile，positive rates of CEA，NSE and CYFRA21-1（32.7%，18.0% and 37.3%）were significantly lower than the targeting antigen to McAb NJ001 in NSCLC（60.7% vs 32.7%，χ2=23.63，P<0.05；60.7% vs 18.0%，χ2=57.22，P<0.05；60.7% vs 37.3%，χ2=16.34，P<0.05）. Conclusions It showed high positive rates of SP70 in the serum of NSCLC patients，which suggested that SP70 might be a potential valuable biomarker for the diagnosis of NSCLC.（Chin J Lab Med，2012,35：554-558） Key words: Lung neoplasms; Carcinoma; non-small-cell lung; HSP70 heat-shock proteins; Tumor markers，biological; Enzyme-linked immunosorbent assay

The tumor markers CEA, CA 19-9, CA-50, CA-195, and TATI were analyzed in patients with pancreatic diseases as well as disorders in the upper quadrant of the abdomen. Two different methods for CA-50, namely CA-50 IRMA and CA-50 DELFIA, which are based on the same monoclonal antibody, were used. The sensitivities, specificities, and predictive values of positive and negative results were calculated at one, three, and ten multiples of the upper reference value ("cutoff") for each method. All the tumor markers except TATI had sensitivities exceeding 90% at one cutoff level, but CEA had low specificity. Poor sensitivities were observed for CEA and TATI at three cutoff levels, whereas CA 19-9, CA-50, and CA-195 had sensitivities and specificities greater than 80%. The sensitivities of these tumor markers decreased at 10 cutoff levels, although the specificities exceeded 95%. The predictive values of positive and negative results were also evaluated at these three cutoff levels. High scores were observed at three cutoff levels. Examined together with the sensitivity and specificity, the evaluation at three cutoff levels indicated that CA 19-9, CA-50, and CA-195 can be used in the diagnostic arsenal for the detection of cancer of the exocrine pancreas in symptomatic patients, and in the differential diagnosis between pancreatic cancer and chronic pancreatitis. Although CA-50 IRMA and CA-50 DELFIA are based on the same monoclonal antibody, there were substantial differences in the levels of CA-50 in a lot of the patients when samples were analyzed by the two methods. These differences were shown to be methodological, and they affected the test evaluations to some extent.

Severe drug-induced thrombocytopenia after treatment with trastuzumab but not with lapatinib

Tissue expression of CA 125 in benign and malignant lesions of ovary and fallopian tube: A comparison with CA 19-9 and CEA

The role of serum tumor markers in non-small cell lung cancer (NSCLC) remains undefined. New proposed markers have seldom been rigorously compared with existing standards. The authors prospectively compared the performance of three new monoclonal antibodies (MoAb) (5E8, 5C7, and 1F10) with the established serum markers carcinoembryonic antigen (CEA) and squamous cell carcinoma antigen (SCC). The cohort consisted of 45 consecutive out-patients with newly diagnosed NSCLC: Control subjects were 38 outpatients with non-neoplastic chronic pulmonary diseases. Blood from each patient and control subject was assayed for all five tumor markers. An enzyme-linked immunosorbent assay (ELISA) was used to determine 5E8, 5C7, and 1F10 reactivity. Commercially available kits were used to measure SCC by radioimmunoassay and CEA by ELISA: Individual and combinations of tumor markers were compared in terms of sensitivity, specificity, and accuracy for NSCLC diagnosis. 5E8 plus 5C7 plus 1F10 significantly surpassed SCC plus CEA in terms of sensitivity (P < 0.05) and proved the most accurate marker combination. Among single markers, 5E8 was most specific, 5C7 most sensitive, and 5C7 and 1F10 each most accurate, but differences from CEA alone were not significant. Subgroup analysis by histologic type and stage demonstrated similar findings, and marker combinations yielded little additional diagnostic benefit. 5E8, 5C7, and 1F10 performed marginally better than did CEA and SCC in patients with newly diagnosed NSCLC: Many limitations apply in defining a clinical niche for these tumor markers in NSCLC, although 5E8, 5C7, and 1F10 previously have demonstrated a modest prognostic value. An adjunctive role in a few specific clinical contexts remains possible.

CA 50 is a new tumor marker based on a monoclonal antibody (MAb) against a human colorectal carcinoma cell line. The CA 50 antigen is similar, but not identical, to the tumor marker CA 19-9. The serum concentrations of CA 50 were measured by an immunoradiometric assay (CA 50 IRMA) in 95 patients with pancreatic cancer and in 94 patients with benign pancreatic, biliary and hepatocellular diseases. The CA 50 concentration was above the cut-off limit of 17 U/ml in 71% of the patients with pancreatic cancer. Elevated CA 50 levels were also seen in 29% of the patients with benign diseases (up to 250 U/ml), especially in patients with extra-hepatic cholestasis (34%) and hepatocellular jaundice (46%). The results of the immunoradiometric assay were compared to those of the commercially available CA 50 RIA inhibition test. The sensitivities of the two CA 50 assays for pancreatic cancer were similar, but the specificity of the IRMA assay was higher. The CA 50 and CA 19-9 values showed a strong positive correlation and the assay parameters of the tests were almost similar. CA 50 seems a promising tumor marker in the detection and follow-up of patients with pancreatic cancer.

Cytokeratin 19 is a subunit of cytokeratin intermediate filament. CYFRA 21-1 is a new tumor marker using monoclonal antibodies which recognize a fragment of cytokeratin 19. CYFRA 21-1 was measured in cytosol of breast cancer tissues or in sera of patients with breast cancer or benign breast diseases to study the significance of this protein as a tumor marker. The cytosol concentration of CYFRA 21-1 was elevated in cancerous tissue compared to that in adjacent noncancerous tissue, and correlated with the tumor stage or the estrogen receptor status. In the serum, the mean value and positive rate for CYFRA 21-1 (assuming 2.2 ng/ml as the cut-off value) were 0.61 ng/ml (0%) in benign breast diseases, 0.98 ng/ml (6.7%) in stage I/II primary breast cancer, 75.67 ng/ml (60.0%) in stage III/IV primary breast cancer, 45.28 ng/ml (60.0%) in recurrent breast cancer, and 0.64 ng/ml (2.6%) in those with no evidence of recurrence. From the above, we concluded that CYFRA 21-1 could be a tumor marker with high specificity in breast cancer.

The clinical use of chemotherapeutic agents against malignant tumors is successful in many cases but suffers from major drawbacks. One drawback is lack of selectivity, which leads to severe side effects and limited efficacy; and another is the emergence/selection of drug-resistance. To limit non-specific toxicity and to improve the efficiency of cancer therapy, "tumor markers", which are proteins generally overexpressed on the surface of tumor cells, can be selectively targeted. Growth factor receptors are one of the most extensively studied tumor markers. The implication of growth factor receptors in the pathogenesis and evolution of cancer has clearly been established and therefore, provides a rationale for therapeutic intervention. The targeting of cytotoxic substances to tumor markers with "magic bullets" is an old idea that raised high expectations but also disappointment. Over the past decade, newly gained understanding of mechanisms for targeted therapy have brought new hopes. Pharmacological agents that selectively target and block the action of growth factors and their receptors have been attempted, such as monoclonal antibodies (mAbs) (whole molecule or fragments), bispecific antibodies, mAbs conjugated to drugs, toxins or radioisotopes, small peptidic and peptidomimetic molecules in free form or conjugated to drugs, anti-sense oligonucleotides, immunoliposomes-encapsulated drugs, and small molecule inhibitors. This review will focus on current developments of selective targeting and bypassing drug resistance in the management of growth factor receptor-overexpressing tumors.

Immunoreactivity of Recombinant Squamous Cell Carcinoma Antigen and Leupin/SCCA-2: Implications for Tumor Marker Detection