Cytokine-regulated expression of activated leukocyte cell adhesion molecule (CD166) on monocyte-lineage cells and in rheumatoid arthritis synovium

OBJECTIVE

To determine whether monocyte/macrophage expression of the CD6 ligand, activated leukocyte cell adhesion molecule (ALCAM) (CD166), is regulated by cytokines during inflammation in rheumatoid arthritis (RA).

METHODS

We used flow cytometry to test whether cytokines present in rheumatoid synovium could regulate ALCAM cell surface expression on peripheral blood (PB) monocytes and RA synovial fluid (SF) macrophages, and we examined ALCAM expression in situ in RA synovium by immunofluorescence.

RESULTS

The monocyte differentiation factors interleukin-3, macrophage colony-stimulating factor (M-CSF), and granulocyte-macrophage colony-stimulating factor augmented ALCAM expression on PB monocytes. ALCAM was expressed on monocyte-lineage cells in situ in inflamed synovium from patients with RA (9 of 9), but not in uninflamed synovium from patients with joint trauma (0 of 3). Furthermore, in vitro culture-induced ALCAM expression on PB monocytes and CD14+ RA SF cells was inhibited by an M-CSF neutralizing antibody.

CONCLUSION

ALCAM expression on PB and SF monocytes/macrophages is enhanced by M-CSF.

Fractalkine and CX3CR1 mediate a novel mechanism of leukocyte capture, firm adhesion, and activation under physiologic flow

Leukocyte migration into sites of inflammation involves multiple molecular interactions between leukocytes and vascular endothelial cells, mediating sequential leukocyte capture, rolling, and firm adhesion. In this study, we tested the role of molecular interactions between fractalkine (FKN), a transmembrane mucin-chemokine hybrid molecule expressed on activated endothelium, and its receptor (CX3CR1) in leukocyte capture, firm adhesion, and activation under physiologic flow conditions. Immobilized FKN fusion proteins captured resting peripheral blood mononuclear cells at physiologic wall shear stresses and induced firm adhesion of resting monocytes, resting and interleukin (IL)-2-activated CD8(+) T lymphocytes and IL-2-activated NK cells. FKN also induced cell shape change in firmly adherent monocytes and IL-2-activated lymphocytes. CX3CR1-transfected K562 cells, but not control K562 cells, firmly adhered to FKN-expressing ECV-304 cells (ECV-FKN) and tumor necrosis factor alpha-activated human umbilical vein endothelial cells. This firm adhesion was not inhibited by pertussis toxin, EDTA/EGTA, or antiintegrin antibodies, indicating that the firm adhesion was integrin independent. In summary, FKN mediated the rapid capture, integrin-independent firm adhesion, and activation of circulating leukocytes under flow. Thus, FKN and CX3CR1 mediate a novel pathway for leukocyte trafficking.

Oxidized alpha2-macroglobulin (alpha2M) differentially regulates receptor binding by cytokines/growth factors: implications for tissue injury and repair mechanisms in inflammation

Alpha2M binds specifically to TNF-alpha, IL-1beta, IL-2, IL-6, IL-8, basic fibroblast growth factor (bFGF), beta-nerve growth factor (beta-NGF), platelet-derived growth factor (PDGF), and TGF-beta. Since many of these cytokines are released along with neutrophil-derived oxidants during acute inflammation, we hypothesize that oxidation alters the ability of alpha2M to bind to these cytokines, resulting in differentially regulated cytokine functions. Using hypochlorite, a neutrophil-derived oxidant, we show that oxidized alpha2M exhibits increased binding to TNF-alpha, IL-2, and IL-6 and decreased binding to beta-NGF, PDGF-BB, TGF-beta1, and TGF-beta2. Hypochlorite oxidation of methylamine-treated alpha2M (alpha2M*), an analogue of the proteinase/alpha2M complex, also results in decreased binding to bFGF, beta-NGF, PDGF-BB, TGF-beta1, and TGF-beta2. Concomitantly, we observed decreased ability to inhibit TGF-beta binding and regulation of cells by oxidized alpha2M and alpha2M*. We then isolated alpha2M from human rheumatoid arthritis synovial fluid and showed that the protein is extensively oxidized and has significantly decreased ability to bind to TGF-beta compared with alpha2M derived from plasma and osteoarthritis synovial fluid. We, therefore, propose that oxidation serves as a switch mechanism that down-regulates the progression of acute inflammation by sequestering TNF-alpha, IL-2, and IL-6, while up-regulating the development of tissue repair processes by releasing bFGF, beta-NGF, PDGF, and TGF-beta from binding to alpha2M.

Overexpression of CD44: a useful independent predictor of prognosis in patients with colorectal carcinomas

BACKGROUND

The goal was to investigate the potential correlation between overexpression of CD44, high microvessel count (MVC), and p21ras with length of relapse-free and overall survival in patients with colorectal adenocarcinomas.

METHODS

CD44, factor VIII-related antigen (FVIII-RA), and p21ras were localized immunohistochemically in patients with colorectal adenomatous polyps (n = 8) and adenocarcinomas (n = 98). The correlation between the expression of CD44, MVC in the areas with highest density, and p21ras with relapse-free and overall survival time was investigated. Data were analyzed statistically using univariate and multivariate systems.

RESULTS

In patients with adenomatous polyps, the positivity of CD44, FVIII-RA, and p21ras was 75%, 62%, and 88%, respectively. In patients with colorectal carcinomas the positivity of CD44 was 55%, and for p21ras it was 52%. The median of FVIII-RA was 4 MVC (range, 0.0 to 32.33). MVC was greater than 4 in 53% of the patients with colorectal carcinomas. In univariate analysis, a significantly longer relapse-free time (CD44: P = .0004; FVIII-RA: P = .0006) and overall survival time (CD44: P = .0001; FVIII-RA: P = .001) were observed for patients with CD44-negative tumors and MVC below 4 as compared to those with CD44-positive tumors and MVC greater than 4. Similar observations were noted in patients with Dukes B and C disease and the rectum as the site of tumor. In multivariate analysis, only CD44 correlated significantly with both relapse-free (P = .0003) and overall survival (P = .00001).

CONCLUSION

Univariate analysis showed CD44 and MVC to be independent predictors of prognosis in colorectal carcinomas. Multivariate analysis showed that CD44 positivity was the most important indicator of an unfavorable prognosis for relapse-free and overall survival in patients with colorectal cancer. Thus, it can be deduced that whether CD44 is positive or negative in patients with colorectal cancer may have prognostic importance and in the future may be used as a factor in the pathologic evaluation of tumor specimens. This hypothesis needs to be tested prospectively in a larger number of patients.

Surgery versus surgery and postoperative radiotherapy in squamous cell carcinoma of the buccal mucosa: a comparative study

BACKGROUND

The efficacy of postoperative radiotherapy for squamous cell carcinoma of the buccal mucosa was evaluated.

METHODS

One hundred seventy-six patients treated between 1989 and 1993 were analyzed. One hundred fifteen patients were treated with surgery alone (Group 1), and 61 patients were treated with a combination of surgery and postoperative radiotherapy (Group 2).

RESULTS

Actuarial 3-year locoregional control in Groups 1 and 2 was 11% and 48% for patients with stage III + IV cancer (P = .001) and 71% and 75% for patients with stage I + II cancer (P = .74), respectively. On multivariate analysis for locoregional failure, surgical margin, bone invasion, high grade, and node involvement were significant factors in Group 1, whereas in Group 2 only tumor thickness was a significant factor. For local failure, margin, bone invasion, and stage in Group 1 and tumor thickness in Group 2 appeared as significant factors. For nodal failure, clinical nodal (cl N0 vs. N+) stage and grade in Group 1 and pathologic nodal stage (pN0 + 1 vs. pN2) in Group 2 were observed as significant factors. On subset analysis, postoperative radiotherapy was observed to have a significant advantage for surgical margins of 2 mm or less in both early pT (T1 + T2) (P = .019) and late pT (T3 + T4) (P = .016) stages. The local failure rate was higher if the time between surgery and radiotherapy was greater than 30 days.

CONCLUSIONS

Postoperative radiotherapy was effective in decreasing locoregional failure in patients with close surgical margins, tumor thicker than 10 mm, high-grade tumors, positive node, and bone invasion. The effect of interval between surgery and postoperative radiotherapy on local failure was margin-dependent.

Protection from pan masala induced genomic damage by beta-carotene and retinoic acid--an in vitro experience

Cytogenetic studies in Chinese hamster ovary (CHO) cells using aqueous and organic extracts of pan masalas, as well as genomic damage observed among pan masala consumers have conclusively shown genotoxic potential of pan masala-a dry complex mixture of areca nut, lime, catechu, cardamom, unspecified flavoring agent, etc., often containing tobacco in it. Tobacco and areca nut, major ingredients of pan masala, are closely associated with oral cancer. The most widely studied group of compounds in the field of chemoprevention is retinoids which includes natural vitamin A, beta-carotene and synthetic derivatives of vitamin A. In the present study, antigenotoxic effect of beta-carotene (BC) and retinoic acid (RA) on genotoxic potential of pan masala have been evaluated in CHO cells with the help of sister chromatid exchange (SCE) frequency and chromosome aberration (CA) frequency as cytogenetic markers. The pulse treatment with pan masala plain/pan masala-tobacco (PM/PMT) extract in combination with either BC or RA yielded lower frequencies of CA and SCE in CHO cells as compared to the cultures treated with aqueous extract fo pan masalas alone. This antigenotoxic effect of BC and RA was more pronounced when treatment was given continuously for a longer duration. Thus, these results indicated possibility of using BC and RA to decrease the risk of oral cancer among pan masala chewers.

Analysis of two duplications of the LDL receptor gene affecting intracellular transport, catabolism, and surface binding of the LDL receptor

Two novel mutations of the low density lipoprotein (LDL)-receptor gene were found in two Italian familial hypercholesterolemia (FH)-heterozygotes. The first mutation was an 18 nucleotide duplication in exon 8 which is preceded by an A-->T transversion. The translation product of the mutant allele was predicted to be a receptor with an in-frame insertion of 6 amino acids in repeat B of the epidermal growth factor precursor homology domain. Analysis of LDL-receptor activity in the proband's fibroblasts showed a 50% reduction of 125I-labeled LDL binding and pulse-chase studies suggested that little, if any, of the mutant protein was processed to the mature form. The second mutation was a 7 kb duplication (from intron 2 to intron 6) of exons 3 through 6, predicted to encode an elongated receptor with the duplication of repeats 2-7 of the ligand binding domain. The elongated receptor was processed slightly more slowly than the normal receptor, but was converted to a mature form of the expected size. This mature, mutant receptor was degraded more rapidly than the normal receptor. On ligand blotting the elongated receptor bound twice as much LDL or beta-very low density lipoprotein (betaVLDL) as the normal receptor. In contrast, maximum binding of LDL to proband's cells was decreased to approximately 70% of the normal cells with a significant increase in apparent affinity. Cell association at 37 degrees C, internalization, and degradation showed a similar reduced maximum. Thus these mutations demonstrate that duplications of amino acid sequences in the low density lipoprotein LDL-receptor may disrupt the LDL-receptor pathway at different levels.

Immunologic characterization of CD7-deficient mice

Human CD7 is an Ig superfamily molecule that is expressed on mature T and NK lymphocytes. Although in vitro studies have suggested a role for CD7 in lymphoid development and function, the exact function of CD7 in vivo has remained elusive. One patient has been reported with SCID syndrome attributed to CD7 deficiency. To study in vivo functions of CD7, we have generated CD7-deficient mice and assessed their lymphoid development and function. CD7-deficient mice were viable, had normal peripheral blood and spleen lymphocyte numbers, and had normal specific Ab responses with Ag-driven Ig isotype switching. Thymocyte numbers were normal in 4-wk-old, 6-mo-old, and 1-yr-old CD7-deficient mice, but in 3-mo-old CD7-deficient mice, total thymocyte numbers were significantly increased by 60% (p < 0.02) compared with normal age-matched +/+ littermates. CD7-deficient splenocytes proliferated normally in response to various mitogens, including PHA, anti-CD3, Con A, and LPS. While NK cell numbers and cytolytic activity to YAC targets were normal, CD7-deficient mice had lower Ag-induced MHC class I-restricted CTL activity against OVA-transfected target cells than did +/+ control mice. Thus, CD7-deficient mice did not have a SCID syndrome, but rather had transient increases in thymocyte numbers at age 3 mo and altered splenocyte Ag-specific CTL effecter cell activity. These data suggest a role for CD7 in regulating intrathymic T cell development and in mediating CTL effecter function.

Seromucoid fraction: a useful biomarker for patients with breast cancer

Seromucoid fraction was measured in terms of mucoid proteins (MP) and hexose content from sera of 1) 47 healthy women, 2) 48 women who had benign breast diseases, 3) 151 untreated patients with breast cancer, and 4) 245 follow-up samples collected from the same breast cancer patients. Mucoid proteins and hexose levels were found to be significantly elevated in untreated patients with breast cancer when compared with the healthy participants (p < 0.001) and patients who had benign breast diseases (p < 0.02 and p < 0.05, respectively). Receiver operating characteristic (ROC) curve analysis revealed potential diagnostic application of both markers for breast cancer. A good correlation was observed between favorable treatment response and decline in serum-marker levels. The markers in patients who did not respond to anticancer therapy remained stable or increased during follow-up. These data indicate that seromucoid fraction can be an useful biochemical marker for breast cancer patients.

CD34+CD38-lin- cord blood cells develop into dendritic cells in human thymic stromal monolayers and thymic nodules

Thymic dendritic cells (DCs) appear to have distinct biologic and functional properties compared with DCs in other tissues. Currently, little is known about human thymic DCs because they have been difficult to isolate and culture in vitro. Here, we report that human thymic stroma can support the development of primitive human hemopoietic stem cells into mature DCs without cytokine or serum supplementation. Coculture of CD34+CD38-lineage (lin)- and CD34+CD38+lin- umbilical cord blood cells with thymic stromal monolayers induced 43 +/- 17-fold and 32 +/- 16-fold expansions, respectively, of umbilical cord blood progenitors and also generated large numbers of cells with the morphologic, phenotypic, and functional characteristics of mature DCs. These cells expressed class I and class II MHC, CD1a, CD2, CD4, CD11c, CD40, CD45, CD80, CD83, and CD86 and were potent stimulators of allogeneic T cell activation. Primitive hemopoietic progenitors also developed into mature DCs in a novel tissue culture system of thymic nodules wherein thymic epithelial cells and fibroblasts were grown in nodular aggregates in vitro. These results demonstrate that human thymic stroma efficiently supports the development of CD34+CD38-lin- cord blood cells into mature DCs. In addition, the culture conditions described in this report are useful systems for studying the ontogeny of human DCs in thymic microenvironments.

Cytogenetic evaluation of 20 sporadic breast cancer patients and their first degree relatives

Many genetic abnormalities disclosed even in somatic cells like peripheral blood lymphocytes may mark footprint(s) of malignancy(ies). The present cytogenetic study on peripheral blood lymphocytes of sporadic breast cancer patients (n = 20) and their first degree relatives (n = 39) reports abnormalities of chromosomes 16, 5, 12, and 17 respectively in 17.59%, 8.33%, 6.48%, and 5.57% cells of patients and 15.83%, 8.33%, 7.5%, and 5% cells of their first degree relatives. These common chromosomal abnormalities pave the way to assume why first degree relatives of sporadic breast cancer patients are at increased risk of developing the same or other malignancies.

Influence of genotype at the low density lipoprotein (LDL) receptor gene locus on the clinical phenotype and response to lipid-lowering drug therapy in heterozygous familial hypercholesterolaemia. The Familial Hypercholesterolaemia Regression Study Group

The relationship between molecular defect and clinical phenotype has been examined in 42 patients with heterozygous familial hypercholesterolaemia (FH) and premature coronary heart disease. The defined defects included mutations in the low density lipoprotein (LDL)-receptor gene (23/42) or the apolipoprotein B Arg3500Gln mutation (5/42). Mean LDL-cholesterol was higher, both before and during treatment with simvastatin and bile acid sequestrants, in patients predicted as having a 'severe' mutation than in those with a 'mild' mutation (8.72 +/- 2.02 mmol/l vs 6.63 +/- 1.8, P = 0.05 before and 4.51 +/- 0.90 mmol/l vs 3.19 +/- 0.58, P = 0.05 during treatment). Maximum inducible LDL-receptor activity in cultured lymphoblasts was inversely correlated with LDL-cholesterol before (r2 = 0.499, P = 0.002) and during (r2 = 0.478, P = 0.004) treatment in patients with a defined mutation in the LDL-receptor gene, but not in the 14 patients with no detectable molecular defect. LDL-cholesterol concentrations before and during treatment were significantly correlated in patients with a defined LDL-receptor gene mutation (r2 = 0.548, P = 0.0001), but not in those with no detectable genetic defect. All these correlations were weak, however and there were no differences in the response to treatment in terms of either relative reduction or absolute decrease in LDL-cholesterol concentration between patients with different LDL-receptor defects. We conclude that only part of the variable phenotype of heterozygous FH patients is explained by different LDL-receptor defects and that other factors determine the severity of their hypercholesterolaemia and the onset of coronary disease.

Prognostic significance of tumor angiogenesis in advanced breast carcinoma: an Indian experience

Angiogenesis is essential for tumor growth and metastasis. In the present study we investigated the prognostic significance of microvessels (MV) density using immunohisto-localization of factor VIII antigen in 51 breast cancer patients. We counted microvessels per 200x field in the most active areas of neovascularization by staining factor VIII related antigen and graded MV density and correlated with stage, LN involvement and histologic grade. Patients who subsequently developed metastases had significantly high MV counts than patients without metastatic disease (p < 0.001). Patients who subsequently died of the disease had significantly high mean microvessels counts than patients who remained alive at the end of 5 years (p < 0.001). As density of factor VIII antigen staining increased the survival decreased (p < 0.001). All the patients having > 25 MV per 200x field had tumor recurrence faster as compared with patients having < 25 MV (p < 0.02). Thus, the MV count correlates with the prediction for metastasis and poor survival. Such an indicator would be useful in selection of a subgroup of patients with breast cancer who are at high risk for having occult metastasis at presentation and subsequently would benefit from aggressive therapy.

Comparison of the genetic defect with LDL-receptor activity in cultured cells from patients with a clinical diagnosis of heterozygous familial hypercholesterolemia. The Familial Hypercholesterolaemia Regression Study Group

In this study we have analyzed the genetic defect in 42 patients with a diagnosis of heterozygous familial hypercholesterolemia (FH) by Southern blotting, SSCP, and sequencing of PCR-amplified fragments of genomic DNA or sequencing of RT-PCR products from mRNA in cultured cells. The apoB Arg3500Gln mutation was identified in five patients. A molecular defect in the LDL-receptor gene was confirmed in 23 patients; 16 of these mutations have not been described before. No defect in the coding region, intron:exon junctions or proximal promoter of the LDL-receptor gene or in the region of the apoB gene coding for the LDL-receptor binding domain was found in the remaining 14 patients. LDL-receptor activity and protein content of cultured lymphoblasts from the patients was significantly lower in cells from patients with severe rather than mild LDL-receptor mutations. Cells from four patients with no detectable defect showed reduced LDL receptor activity compared with eight normal cell lines, whereas six others had reduced LDL-receptor activity but LDL-receptor protein content within the normal range. Cells from four patients appeared to have normal LDL-receptor function. Cells from two patients with a defined defect also had LDL-receptor activity within the normal range. The findings demonstrate the problems involved in the genetic diagnosis of FH in patients.

Thymocytes and cultured thymic epithelial cells express transcripts encoding alpha-3, alpha-5 and beta-4 subunits of neuronal nicotinic acetylcholine receptors: preferential transcription of the alpha-3 and beta-4 genes by immature CD4 + 8 + thymocytes

Thymic tissues express transcripts encoding the alpha-3, alpha-5 and beta-4 subunits of nicotinic neuronal acetylcholine receptors (AcChRs) suggesting that neuronal AcChRs similar to those expressed in ganglia are expressed in the thymus. Transcription occurs in both isolated thymocytes and thymic epithelial cells. RT-PCR analyses of thymocyte subsets indicate that immature CD4 + 8 + thymocytes express higher levels of the alpha-3 and beta-4 transcripts than more mature thymocytes. Compared to freshly isolated thymocytes, peripheral blood lymphocytes do not express alpha-3 and beta-4 AcChR subunit transcripts. Cultured thymocytes rapidly down-regulate transcription of the alpha-3 and beta-4 AcChR subunit genes by a process that is not reversed by stimulation with phytohemagglutinin and IL-2. Thus our results indicate that there is transcriptional regulation of neuronal AcChR subunit genes during the process of thymocyte maturation and that factors within the thymic microenvironment influence expression of the alpha-3 and beta-4 AcChR subunit genes by developing T cells.

CD6-ligand interactions: a paradigm for SRCR domain function?

The scavenger receptor cysteine-rich (SRCR) superfamily, which includes proteins expressed by leukocytes, can be subdivided into groups A and B. Group B contains the lymphocyte cell-surface receptor CD6. This article reviews recent progress in understanding the interaction between CD6 and its ligand, activated leukocyte cell adhesion molecule (ALCAM). Analysis of the CD6-ALCAM interaction may help to understand how other SRCR domains bind to their ligands.

DNA repair proficiency in breast cancer patients and their first-degree relatives

Defective DNA repair capacity as measured by enumerating chromatid aberrations induced in G2 phase by X-irradiation may explain increased risk of breast cancer among relatives of patients. In the present study, chromatid damage was determined in peripheral blood lymphocytes (PBL) following in vitro exposure to 50R X-irradiation in G2 phase from 14 breast cancer (BrCa) patients, 19 first-degree relatives (FDR) of BrCa patients and 17 control women who had no family history of cancer for the last 3 generations. Controls, BrCa patients and their FDR had comparable frequency of gaps and breaks when cells were arrested with Colcemid (30 min) after X-irradiation. A steep decline in chromatid damage was observed in cells of controls when arrested after 30, 90 and 120 min of X-irradiation. BrCa patients and their FDR showed higher frequencies of lymphocytic chromatid damage as compared to controls. Chromatid damage (95 gaps + breaks per 100 cells) observed among controls at 90 min post X-irradiation was considered as the optimal level of efficient DNA repair. Thirty-five percent of controls, 93% of BrCa patients and 79% of FDR showed sub-optimal DNA repair. Amongst the FDR, the likelihood of having suboptimal DNA repair was 7 times higher and the risk of developing breast cancer was 2.7 times higher as compared to controls. Moreover, in the BrCa patients, there was frequent involvement of chromosomes 1 and 2, and chromosomes of B, D and E groups, while in FDR, involvement of chromosome 2 and chromosomes of B, D and E groups was more frequent.

Expression of CD44 and variant isoforms in cultured human retinal pigment epithelial cells

PURPOSE

CD44 is a major hyaluronic acid receptor that exists as a number of isoforms, generated by alternative splicing of 9 "variant" exons in humans (v2 to v10) and 10 exons in rodents. Little is known about the expression and function of CD44 in human retinal pigment epithelium (RPE) cells. Therefore, the authors determined whether human RPE cells express CD44, and whether the expression differs depending on the proliferative status of the cells.

METHODS

Human RPE cells were harvested from normal donor eyes and propagated in culture. Total RNA was extracted from cultured cells. mRNA expression of CD44 was determined by reverse transcription-polymerase chain reaction (RT-PCR), followed by cloning and sequencing of the PCR products, and by Southern hybridization. CD44 cell surface expression was measured by flow cytometry. Western hybridization and immunohistochemistry were used to determine the CD44 immunoreactivity of cultured human RPE cells and normal human RPE cells in situ.

RESULTS

The standard form of CD44 mRNA and variant isoforms containing exon v6 or v10 were expressed in cultured human RPE cells. CD44 mRNA and protein levels were increased in proliferating human RPE cells compared with density-arrested counterparts. Addition of 1 microM retinoic acid enhanced the cell density-induced downregulation of CD44 mRNA, but did not significantly affect the CD44 cell surface protein expression. As previously reported, CD44 immunoreactivity was not detected in normal human RPE cells in situ.

CONCLUSIONS

Cultured human RPE cells express CD44 standard form and variant isoforms containing exon v6 or v10, which are preferentially expressed by proliferating human RPE cells.

Haemangiopericytoma: current status, diagnosis and management

Haemangiopericytoma (HPC) is a rare tumour, characterized by unidentifiable light microscopic features. Despite first being described over 50 years ago, nothing much was known about this tumour until the early 1980s, when ultrastructural studies and tumour markers made it possible to differentiate it from other mesenchymal tumours. Advancements in radiology and the emergence of MRI technology helped surgeons in better planning. Pre-operative vascular embolization helped to reduce the menace of operative haemorrhage. Improvements in localization and delivery of radiotherapy, coupled with early diagnosis, has tremendously improved the treatment outcome of haemangiopericytoma.

Coexpression of Bcl-2, c-Myc, and p53 oncoproteins as prognostic discriminants in patients with colorectal carcinoma

PURPOSE

This study was undertaken to evaluate the clinical use of Bcl-2, c-Myc, and p53 oncoproteins, either singly or in combination, as prognostic discriminants relative to recurrence and overall survival in patients with Dukes B or C colorectal carcinoma.

METHODS

Analyses were made on archival pathology tissues of 48 patients with colorectal cancer. The oncoproteins were localized using commercially available monoclonal antibodies: clone 124 for Bcl-2, 9E11 for c-Myc, and DO-7 for p53. The avidin-biotin peroxidase complex method was used. Patients were followed up for a period of 2 to 36 months.

RESULTS

Expression of Bcl-2 and c-Myc was cytoplasmic, whereas nuclear p53 immunoreactivity was localized in the tumor cells. Sixty percent (29/48), 65 percent (31/48), and 37 percent (18/48) of the tumors showed overexpression of Bcl-2, c-Myc, and p53 oncoproteins, respectively. Fifty-four percent (18/33) and 100 percent (9/9) of moderately and poorly differentiated tumors, respectively, were positive for Bcl-2 (P < 0.01). No such correlation was noted for c-Myc and p53 oncoproteins. Univariate analysis showed that patients with Bcl-2 and c-Myc overexpression were associated with poorer overall survival than patients with Bcl-2-negative (P < 0.0124) and c-Myc-negative (P < 0.036) tumors. In addition, when patients were subgrouped according to Dukes stage, a statistically significant poorer overall survival was observed in Dukes C patients with Bcl-2-positive tumors (P < 0.017). Furthermore, multivariate analysis revealed that coexpression of three oncoproteins was predictive of a worse prognosis than for those individuals expressing none of the oncoproteins (P < 0.031) and only one positive oncoprotein (P < 0.014).

CONCLUSION

These findings suggest that oncoprotein coexpression possesses significant prognostic and potential therapeutic value; incorporation of molecular markers into future prospective randomized trials is advisable.

Synthesis and properties of the very-low-density-lipoprotein receptor and a comparison with the low-density-lipoprotein receptor

The properties of the very-low-density lipoprotein (VLDL) receptor have been studied in Chinese hamster ovary (CHO) cells stably transfected with human VLDL-receptor cDNA and compared with those of the low-density lipoprotein (LDL) receptor expressed under the same conditions. Immunoblotting showed that the cells produced a mature VLDL receptor protein, of apparent Mr 123000 on non-reduced and 158000 on reduced gels, that was less extensively glycosylated than the LDL receptor. The VLDL receptor was more slowly processed than the LDL receptor, with only approx. 70% of the precursor being converted into the mature protein. Nevertheless, the majority of the receptor in the cells was in the mature form, and most of this was present on the cell surface. The human VLDL receptor bound rabbit very-low-density lipoprotein with beta electrophoretic mobility (betaVLDL), but not human LDL, and uptake through the receptor led to stimulation of oleate incorporation into cholesteryl esters. At 37 degrees C, the characteristics of VLDL-receptor-mediated uptake and degradation of betaVLDL were essentially the same as those mediated by the LDL receptor. However, the VLDL receptor apparently did not show the increase in affinity and decrease in binding of betaVLDL on cooling to 4 degrees C that was exhibited by the LDL receptor. Thus the overexpressed VLDL receptor in CHO cells appears to behave as a lipoprotein receptor with similar, but not identical, properties to the LDL receptor.

Clinical significance of p53, nm23, and bcl-2 in T3-4N1M0 oesophageal carcinoma: an immunohistochemical approach

BACKGROUND AND OBJECTIVE

The purpose of this retrospective study was to test whether the expression of p53, nm23, and bcl-2 in T3-4N1M0 oesophageal carcinoma is associated with patient survival.

METHODS

Immunohistochemical localisation of p53, nm23, and bcl-2 was performed on formalin-fixed, paraffin-embedded tissue sections (N = 46). The observed range of follow-up period was 0.2-24.0 months with a median of 11.0 months. A total of 85% (39/46) of the patients died within 24.0 months, which could be due to advanced disease at presentation. The immunohistochemical signal was expressed as the proportion of positive cells. The immunostaining for p53 was nuclear, whereas that for nm23 and bcl-2 was cytoplasmic in the neoplastic cells.

RESULTS

p53 was expressed in 70% (32/46) of cases; nm23 in 29% (13/45), and bcl-2 in 67% (29/43) of tumours. The univariate analysis showed that the expression of two markers, i.e., expression of p53 and absence of nm23 were independently associated with unfavourable overall survival time. Despite a small number of patients treated with adjuvant therapy, we observed that tumours positive for p53 had an unfavourable prognosis when compared with tumours negative for p53.

CONCLUSIONS

Our preliminary findings suggest: expression of p53 and nm23 negativity may be related to an unfavourable prognosis in patients with advanced oesophageal carcinoma.

Glycoprotein electrophoretic pattern in sera of patients with oral precancerous conditions and upper aerodigestive tract cancer

Cancer of the upper aerodigestive tract is one of the leading sites of human malignancies in India. Various glycoproteins have been claimed to be specifically associated with cancer. Serum glycoprotein electrophoresis was carried out in sera obtained from 23 healthy individuals [10 without habit of tobacco consumption (NHT) 13 with habit of tobacco consumption (WHT)], 46 patients with oral precancerous conditions (OPC) and 110 untreated patients with upper aerodigestive tract cancer. Eighty-six samples from the cancer patients were also collected after initiation of anticancer therapy. The albumin, alpha, beta and gamma region glycoproteins were quantitated by densitometric scanning after separation by polyacrylamide disc gel (PADG) electrophoresis. Mean values of albumin and alpha region glycoproteins were significantly lower in WHT and patients with OPC as compared to NHT. The gamma region glycoproteins were significantly elevated in WHT, patients with OPC and untreated cancer patients as compared to the NHT. The albumin region glycoproteins were significantly low, whereas, gamma region glycoproteins were significantly elevated in nonresponders as compared to their pretreatment levels. The glycoprotein values in complete responders were comparable with NHT. An extra glycoprotein band was found in the post beta region, in most of the individuals (>50%) with habit of tobacco consumption in all the groups. There was a decrease in the albumin/gamma, alpha/gamma and beta/gamma values in patients with OPC as well as untreated cancer patients as compared to NHT. Albumin/gamma, alpha/gamma and beta/gamma values were lower in nonresponders as compared to their pretreatment value. The results indicate that the alterations in glycoprotein electrophoresis pattern may be useful for early detection of cancer of the upper aerodigestive tract. It may also be helpful in treatment monitoring of cancer patients.