Cancer genes: current status, future prospects, and applications in radiotherapy/oncology

Potential Biological Markers for the Staging of Tumor Progression in Oral Mucosa: A Multivariate Analysis

A recent trend in cancer control programmes is the development of early detection strategies and chemoprevention of premalignant lesions. The present study evaluates the potential of selected markers in the biological staging of tumor progression in oral mucosa for better management of the disease. The expression patterns of various cytokeratin protein types such as 10/11, 13 & 16, 19, 18, 14 and pancytokeratin, involucrin, ras p21, epidermal growth factor (EGF) and its receptor (EGFR) were assessed immunohistochemically in various stages of tumor progression in oral mucosa. Statistical analyses such as the Kruskal-Wallis one-way ANOVA, Spearman's rank correlation and multiple regression analysis were carried out to see which proteins have a significant association with tumor progression in oral mucosa. Statistical analysis showed that the expression patterns of cytokeratin types 10/11, 14 and 19, involucrin and epidermal growth factor were significantly correlated with tumor progression in oral mucosa in both univariate and multivariate analysis. Thus the biological stage of a lesion can be calculated from the multiple regression equation derived for these proteins, which could be more useful in assessing the stage of tumor progression in oral mucosa than histopathological grading.

HSP72 and gp96 in gastroenterological cancers

Heat shock protein 72 (HSP72) and glycoprotein 96 (gp96) are highly expressed in cancer tissues. Recent studies indicate the possible roles of HSP72 and gp96 in the development and progression of gastrointestinal carcinomas but detailed mechanisms are still ambiguous. Human esophageal cancer, gastric cancer, colon cancer and liver cancer are common gastrointestinal malignant carcinomas in the world. The studies indicated that there existed a significant correlation between the expression of HSP72, gp96 and the development and progression of digestive carcinomas. HSP72 and gp96 expression were significantly associated with the presence of tumor infiltration, lymph node and remote metastasis. Interestingly, studies have found that HSP72 chaperoned alpha-fetoprotein (AFP), HBx in hepatocellular carcinoma, and CD44 in colonic carcinomas. The further researches demonstrated that HSP72-AFP or gp96-AFP recombined vaccine could elicit specific anti-tumor immunity. The high-level expression of HSP72 and gp96 may be not only used as diagnostic or prognostic markers for gastrointestinal carcinomas but also as better immunotherapeutic vaccines in the cancers.

Investigation of NK cell function and their modulation in different malignancies

NK cells have become a subject of investigation not only in the field of tumor immunology and infectious diseases, but also within all aspects of immunology, such as transplantation, autoimmunity, and hypersensitivity. Our early studies aside from investigating NK cell activity in experimental animals and humans included studies of perforin expression and modulation in this lymphocyte subset. As NK cell activity is modified by their environment, we showed clinical stage-dependent impairment of their activity and in vitro effect of different sera, Th1 cytokines, and their combination in breast cancer, Hodgkin's disease, and non-Hodgkin's lymphoma patients, especially with respect to metabolic and cell membrane changes of peripheral blood lymphocytes evaluated by spontaneous release of the enzyme lactate dehydrogenase (LDH) that led to the correction of the LDH enzyme release assay for natural cytotoxicity. By long-term immuno-monitoring of patients with malignancies, we also showed the kinetics of NK cell modulation during chemo-immunotherapy. In our more recent studies, we give data of NK function and novel families of NK cell receptor expression in healthy individuals that may be of help in NK cell profiling, by giving referent values of basic and cytokine-induced expression of some NK cell receptors either in evaluation of disease or in immuno-monitoring during cytokine therapy of patients with malignancies. Moreover, we give novel aspects of modulation of NK cell activity by cytokines approved for immunotherapy, IFN and IL-2, in melanoma and other malignancies with respect to alterations in new activating (NKG2D and CD161) and inhibitory (CD158a and CD158b) receptor characteristics and signaling molecules in CD16- and CD56-defined NK cells and their small immunoregulatory and large cytotoxic subsets in peripheral blood and lymph nodes, as NK cell-mediated killing of tumor cells depends on the balance between stimulatory and inhibitory signaling.

Correlation between clinicopathology and expression of heat shock protein 72 and glycoprotein 96 in human esophageal squamous cell carcinoma

Heat shock protein 72 (HSP72) and glycoprotein 96 (gp96) are highly expressed in cancer tissues. Recent studies indicate the possible roles of HSP72 and gp96 in the development and progression of gastrointestinal carcinomas but detailed information is still ambiguous. We investigated the correlation between clinicopathology and expression of HSP72 and gp96 in human esophageal squamous cell carcinoma. The expression of HSP72 and gp96 was studied in 120 human esophageal squamous cell carcinomas with or without metastasis as well as in mucous membrane adjacent to cancers by way of immunohistochemistry. HSP72 immunoreactivities were detected in 112 of 120 primary tumors (93.3%) and in 30 of 120 mucous membranes adjacent to cancers (25.0%). Gp96 detected in esophageal squamous cell carcinoma and inmucous membrane adjacent to cancer was 85.0% and 20.0%, respectively. Both HSP72 and gp96 stained in cytoplasm. HSP72 and gp96 expression in esophageal squamous cell carcinomas withmetastasis was significantly higher than those with nonmetastasis (P < .05). The results indicate that there exists a significant correlation between the expression of HSP72 and gp96 and the progression of esophageal squamous cell carcinomas. HSP72 and gp96 expression were significantly associated with the presence of tumor infiltration, lymph node, and remote metastasis.

Immunolocalisation of heat shock protein 72 and glycoprotein 96 in colonic adenocarcinoma

Heat shock protein 72 (HSP72) and glycoprotein 96 (gp96) are highly expressed in cancer tissues. Recent studies indicate the possible roles of HSP72 and gp96 in the development and progression of colonic carcinomas, but detailed information is still ambiguous. In this study, we investigated the correlation between clinical pathology and immunolocalisation of HSP72 and gp96 in human colonic carcinoma. The distribution of HSP72 and gp96 was studied in 160 human colonic carcinomas, with or without metastasis, as well as in mucous membranes adjacent to cancers by means of immunohistochemistry. HSP72 immunoreactivity was detected in 145 of 160 primary tumours (90.6%) and in 44 of 160 mucous membranes adjacent to cancers (27.5%). Gp96 was detected in 81.3% colonic carcinomas and in 13.8% mucous membranes adjacent to cancer. Immunolocalisation of HSP72 and gp96 was mainly cytoplasmic. HSP72 and gp96 immunolabelling was significantly higher in colonic carcinomas with metastasis than in those without metastasis (P<0.05). The results indicate a significant correlation between the immunopositivity of HSP72 and gp96 and the progression of colonic carcinomas. Immunolabelling of HSP72 and gp96 may be useful as diagnostic or prognostic markers in colonic carcinoma.

Correlation between clinicopathology and expression of heat shock protein 72 and glycoprotein 96 in human gastric adenocarcinoma

Heat shock protein 72 (HSP72) and glycoprotein 96 (gp96) are highly expressed in cancer tissues. Recent studies indicate the possible roles of HSP72 and gp96 in the development and progression of gastric carcinomas but detailed information is still ambiguous. In this study, we investigated the correlation between clinicopathology and expression of HSP72 and gp96 in human gastric carcinoma. The expression of HSP72 and gp96 was studied in 60 human gastric carcinomas with or without metastasis as well as in mucous membrane adjacent to cancers by way of immunohistochemistry. HSP72 immunoreactivities were detected in 54 of 60 primary tumors (90.0%) and in 22 of 60 mucous membranes adjacent to cancers (36.7%). Likewise, gp96 immunoreactivities were detected in 49 cases of gastric carcinoma (81.7%) and in 15 samples of mucous membrane adjacent to cancer (25.0%). Both HSP72 and gp96 were stained in cytoplasm. HSP72 and gp96 expression in colonic carcinomas with metastasis was significantly higher than those with non-metastasis (p < 0.05). The results indicate that there exists a significant correlation between the expression of HSP72 and gp96 and the progression of gastric carcinomas. The high-level expression of HSP72 and gp96 may be used as diagnostic or prognostic markers for gastric carcinoma.

Co-expression of heat shock protein 70 and glucose-regulated protein 94 in human gastric carcinoma cell line BGC-823

AIM: To investigate the co-expression and significance of heat shock protein 70 (HSP70) and glucose-regulated protein 94 (grp94) in human gastric carcinoma cell line BGC-823.

METHODS: The expression and localization of HSP70 and grp94 in human gastric carcinoma cell line BGC-823 were determined by immunocytochemistry and indirect immunofluorescence cytochemical staining. Flow cytometry was used to analyze the correlation between expression of HSP70, grp94 and cell cycle in BGC-823 cell line.

RESULTS: Gastric cancer cell line BGC-823 expressed high level of HSP70 and grp94. The positive rate of HSP70 and grp94 was 84.9±4.94% and 79.6±5.16%, respectively. Both of them were stained in cell plasma. There was a significant difference compared with control group (1.9±0.94%, P<0.01). During the cell cycle, HSP70 and grp94 were continuously expressed in BGC-823.

CONCLUSION: HSP70 and grp94 are highly expressed in human gastric carcinoma BGC-823 cells through the whole cell cycle. There is no relationship between expression of HSP70, grp94 and cell cycle.

Correlation between clinicopathology and expression of heat shock protein 70 and glucose-regulated protein 94 in human colonic adenocarcinoma

AIM: To investigate the correlation between clinicopathology and expression of heat shock protein 70 (HSP70) and glucose-regulated protein 94 (grp94) in human colonic carcinoma.

METHODS: The expression of HSP70 and grp94 was studied in 80 human colonic cancers with or without metastasis as well as in their adjacent mucous membrane by way of immunohistochemistry and pathology photograph analysis.

RESULTS: The expression of HSP70 and grp94 was significantly higher in cancer than that in adjacent mucous membrane (92.5%, 85.0% vs 56.3%, 42.5%, P<0.01). HSP70 and grp94 expressed higher in moderately- and poorly-differentiated colonic cancers than that in their adjacent tissues (93.7%, 87.5%; 100%, 90% vs 56.3%, 42.5%; P<0.01). Dukes C and D stages of colonic cancers showed higher positive rates than Dukes A and B stage groups (97.1%, 91.2%; 100%, 90.9%; vs 80%, 70%; 78.6%, 71.4%; P<0.05). There were definite differences in HSP70 and grp94 expression between metastasis groups and non-metastasis groups (100% vs 75%, 100% vs 50%, P<0.05).

CONCLUSION: The HSP70 and grp94 expression rates in colonic cancer groups are significantly higher than that in their adjacent mucous membrane. The HSP70 and grp94 expression in poorly-differentiated colonic cancers with metastasis is significantly higher than well-differentiated cancers without metastasis. The overexpression of HSP70 and grp94 can be used as diagnostic or prognostic markers for colonic cancer.

The genotype of the human cancer cell: implications for risk analysis

An extremely large database describes genotypes associated with the human cancer phenotype and genotypes of human populations with genetic predisposition to cancer. Aspects of this database are examined from the perspective of risk analysis, and the following conclusions and hypotheses are proposed: (1) The genotypes of human cancer cells are characterized by multiple mutated genes. Each type of cancer is characterized by a set of mutated genes, a subset from a total of more than 80 genes, that varies between tissue types and between different tumors from the same tissue. No single cancer-associated gene nor carcinogenic pathway appears suitable as an overall indicator whose induction serves as a quantitative marker for risk analysis. (2) Genetic defects that predispose human populations to cancer are numerous and diverse, and provide a model for associating cancer rates with induced genetic changes. As these syndromes contribute significantly to the overall cancer rate, risk analysis should include an estimation of the effect of putative carcinogens on individuals with genetic predisposition. (3) Gene activation and inactivation events are observed in the cancer genotype at different frequencies, and the potency of carcinogens to induce these events varies significantly. There is a paradox between the observed frequency for induction of single mutational events in test systems and the frequency of multiple events in a single cancer cell, suggesting events are not independent. Quantitative prediction of cancer risk will depend on identifying rate-limiting events in carcinogenesis. Hyperproliferation and hypermutation may be such events. (4) Four sets of data suggest that hypermutation may be an important carcinogenic process. Current mechanisms of risk analysis do not properly evaluate the potency of putative carcinogens to induce the hypermutable state or to increase mutation in hypermutable cells. (5) High-dose exposure to carcinogens in model systems changes patterns of gene expression and may induce protective effects through delay in cell progression and other processes that affect mutagenesis and toxicity. Paradigms in risk analysis that require extrapolation over wide ranges of exposure levels may be flawed mechanistically and may underestimate carcinogenic effects of test agents at environmental levels. Characteristics of the human cancer genotype suggest that approaches to risk analysis must be broadened to consider the multiplicity of carcinogenic pathways and the relative roles of hyperproliferation and hypermutation. Further, estimation of risk to general human populations must consider effects on hypersusceptible individuals. The extrapolation of effects over wide exposure levels is an imprecise process.

An initiation-promotion model of tumour prevalence from high-charge and energy radiations

A repair/misrepair kinetic model for multiple radiation-induced lesions (mutation inactivation) is coupled to a two-mutation model of initiation-promotion in tissue to provide a parametric description of tumour prevalence in the mouse Harderian gland from high-energy and charge radiations. Track-structure effects are considered using an action-cross section model. Dose-response curves are described for gamma rays and relativistic ions, and good agreement with experiment is found. The effects of nuclear fragmentation are also considered for high-energy proton and alpha-particle exposures. The model described provides a parametric description of age-dependent cancer induction for a wide range of radiation fields. Radiosensitivity parameters found in the model for an initiation mutation (sigma 0 = 7.6 x 10(-10) cm2 and D0 = 148.0 Gy) are somewhat different than previously observed for neoplastic transformation of C3H10T1/2 cell cultures (sigma 0 = 0.7 x 10(-10) cm2 and D0 = 117.0 Gy). We consider the two hypotheses that radiation acts solely as an initiator or as both initiator and promoter and make model calculations for fractionation exposures from gamma rays and relativistic Fe ions. For fractionated Fe exposures, an inverse-dose-rate effect is provided by a promotion hypothesis with an increase of 30% or more, dependent on the dose level and fractionation schedule, using a mutation rate for promotion similar to that of single-gene mutations.

Polymerase chain reaction-based restriction fragment length polymorphism analysis of the short arm of chromosome 3 in primary head and neck squamous carcinoma

BACKGROUND

Deletion or loss of heterozygosity (LOH) at the polymorphic loci on the short arm of chromosome 3 has been reported in a large number of renal cell, small cell lung, non-small cell lung, and cervical carcinomas, suggesting the presence of one or more putative tumor suppressor genes at chromosome 3p. Similar studies in primary head and neck carcinoma are lacking.

METHODS

To investigate the possibility of chromosome 3p deletions, the authors applied a polymerase chain reaction (PCR)-based, restriction fragment length polymorphism analysis, in conjunction with conventional Southern blot techniques, to DNA samples of matched normal mucosa and head and neck squamous cell carcinomas from 18 patients. The authors also assessed the merit of the PCR-based assay as a rapid screening tool, particularly in assaying limited tissue samples.

RESULTS

Constitutional heterozygosity at the polymorphic loci varied in the 18 normal samples that the authors studied: 12 at the D3F15S2 locus (on telomeric 3p21), 7 at the D3S32 locus (on centromeric 3p21), and 9 at the THRB locus (on 3p24). In 18 matched carcinoma specimens, LOH (deletion) was observed at D3S32 in 0 of 7, at D3F15S2 in 9 of 12 (75%), and at THRB in 3 of 9 cases (33%).

CONCLUSIONS

The results of the PCR-based assay and Southern blotting were completely concordant in all specimens the authors studied. This study indicates that deletion at 3p is a frequent abnormality in primary head and neck carcinoma and that the most common deletion region is telomeric to D3S32. The authors also observed an apparent correlation among poor histologic differentiation, DNA aneuploidy, and 3p deletions. Most poorly and moderately differentiated and aneuploid carcinomas manifested the 3p deletion. Therefore, the authors suggest an association between deletion at 3p and aggressive biologic behavior.

Bilateral renal oncocytomas: management and nuclear analysis

Only 16 cases of bilateral renal oncocytomas have been previously reported in the English language literature, 9 of which were treated with bilateral surgical resections. We report a case treated with bilateral partial nephrectomy. Although pathological examination revealed grade I oncocytomas on both sides, flow cytometry demonstrated tumor DNA content to be aneuploid on one side and diploid on the other, the first cellular differences reported in a case of bilateral renal oncocytomas. The management of suspected renal oncocytomas is discussed, with emphasis on the need for complete excision in most patients. The results of nuclear studies of these tumors, including DNA flow cytometry, cytogenetics, and molecular analysis of both nuclear and mitochondrial DNA, are reviewed.