Comparison of flow cytometric DNA content in primary gastric carcinoma and metastases

DKC1 enhances angiogenesis by promoting HIF-1α transcription and facilitates metastasis in colorectal cancer

BACKGROUND

Dyskeratosis congenita 1 (DKC1) is dysregulated in several cancers. However, the expression and function of DKC1 in colorectal cancer (CRC) is rarely reported.

METHODS

Tissue microarrays (TAMs) including 411 cases of CRC tissues and corresponding paracancerous tissues were used to examine the DKC1 expression. The correlations between the DKC1 expression and clinicopathological or survival characters were further analysed. The functions and molecular mechanism of DKC1 in CRC were investigated through a series of in vitro and in vivo experiments.

RESULTS

The result showed that DKC1 expression was increased in CRC tissues. Increased DKC1 expression was associated with high grade of TNM stage, additional lymph node metastasis, and poor prognosis of patients with CRC. Multivariate COX analysis indicated that DKC1 can act as an independent prognostic factor for patients with CRC. DKC1 also facilitated the CRC angiogenesis and metastasis by increasing HIF-1α and VEGF expression levels. Chromatin immunoprecipitation assay demonstrated that DKC1 facilitated HIF-1α expression by regulating HIF-1α promoter activity.

CONCLUSION

DKC1 appears to regulate CRC angiogenesis and metastasis through directly activating HIF-1α transcription. DKC1 can serve as an accurate indicator in predicting the prognosis of patients with CRC and act as a potential therapeutic target for CRC.

DNA ploidy and its clinical implications in gastric cancer

BACKGROUND

Biological characteristics of gastric cancer depend mostly on genetic alterations in the cancer cells of individuals. To precisely predict the biological behavior and clinical outcome of individual cancer, it may be important to clarify the DNA profiles of cancer cells in each case.

METHODS

We have reviewed the most important results of studies on DNA ploidy of gastric cancer published in the English literature during the last 2 decades.

RESULTS

Gastric carcinoma with aneuploidy has been shown to have a high proliferative activity and a high metastatic or invasive potential, thus leading to a poor prognosis as compared to diploid tumors.

CONCLUSION

Analyses of DNA ploidy in gastric cancer may provide clinically useful information on diagnostic, therapeutic, and prognostic aspects. Further investigations may be needed to clarify the relationship between chromosome instability and DNA ploidy.

Expression of proliferating cell nuclear antigen and CD44 variant isoforms in the primary and metastatic sites of nonsmall cell lung carcinoma with intrapulmonary metastases

BACKGROUND

To the authors' knowledge the prognosis of patients with intrapulmonary metastases (PM) of nonsmall cell lung carcinoma (NSCLC) has not yet been clarified fully and little is known regarding the characteristic changes that occur during the metastatic process, nor of their clinical significance.

METHODS

Formalin fixed and paraffin embedded material of primary and metastatic lesions resected from 34 patients with PM of NSCLC were stained immunohistochemically with proliferating cell nuclear antigen (PCNA) and CD44 and its variant isoforms.

RESULTS

Patients with NSCLC expressing PCNA in the primary tumor site (79.4%) showed a significantly poorer survival (5-year survival rate of 20.2%) compared with the 5-year survival rate of 57.1% for patients not expressing PCNA in the primary tumor site (P = 0.048). Patients expressing PCNA in the metastatic site (88.2%) also showed a significantly poorer prognosis than those not expressing PCNA (P = 0. 036). Patients with squamous cell carcinoma expressed CD44 variant exon 6 (CD44v6) at a significantly higher rate than adenocarcinoma patients (P = 0.0164), but expression of CD44v6 was not a significant prognostic factor. Concordance of PCNA and CD44v6 expression between the primary and corresponding metastatic sites was observed in 65% of patients (22 of 34 patients) but no difference in prognosis was observed in relation to this concordance. Cox multivariate analyses indicated that expression of PCNA was a significant prognostic indicator for both primary and metastatic sites (P = 0.014 and P = 0.0095, respectively).

CONCLUSIONS

This study demonstrated that PCNA expression was a significant prognostic factor for both primary and metastatic lesions in PM patients. CD44v6 showed histogenesis of the tumor, but no relation with the prognosis could be ascertained.

Change of flow cytometric DNA content in para-aortic lymph node showing recurrence after adjuvant chemotherapy for gastric cancer

A para-aortic lymph node showing recurrence was resected from a patient who had received adjuvant chemotherapy after curative resection of an advanced gastric cancer. A flow cytometric analysis of DNA content was carried out for the primary lesion, a metastatic lymph node and the resected lymph node. A peri-diploid cell population in addition to diploid cells appeared in the recurrent lesion, whereas a major diploid cell population and a minor aneuploid cell population were found in the primary lesion and the metastatic lymph node, indicating that a clone of chemo-resistant tumor cells selectively multiplied after the cytotoxic therapy. The characters of a recurrent lesion may be changed by clonal selection following chemotherapy.

Flow cytometric analysis of the DNA content in primary and metastatic lesions of colorectal cancer

We investigated and compared the DNA content between primary and metastatic lesions from 30 colorectal cancer cases. The findings were only diploid in 2 cases (6.7%) and only aneuploid in 18 cases (60.0%). On the whole, the DNA ploidy agreed in 20 cases (66.7%) between both lesions. In the 18 cases with only aneuploid tumors in both lesions, the DNA index tended to be larger in the metastatic lesions than in the primary lesions. In contrast, a variation in the DNA ploidy was observed in 10 cases (33.3%). These findings show that DNA ploidy tends to remain stable during metastasis in many cases of colorectal cancer, although the DNA index did tend to be larger in metastatic lesions than in primary lesions. The existence of intertumoral heterogeneity in the DNA ploidy also shows that specimens should be investigated from both lesions in order to obtain more accurate information on the tumor and its biological behavior.

DNA aneuploidy in gastric carcinoma. Flow cytometric data related to survival, location, and histopathologic findings

BACKGROUND

The aim of the study was to evaluate the prognostic significance of DNA ploidy of gastric carcinomas.

METHODS

The DNA content was analyzed by flow cytometry on archival paraffin-embedded material from tumors of 97 consecutive patients.

RESULTS

A multivariate analysis showed that the DNA ploidy pattern and lymph node metastasis were the only independent prognostic markers for survival (p = 0.01 and p = 0.02, respectively). The relative risk of death due to gastric cancer was three times greater for patients with DNA hypertetraploid tumors than for patients with DNA diploid tumors and twice as high for patients with lymph node metastasis as for patients without. Well and moderately differentiated carcinomas were more frequently aneuploid than tumors with poor differentiation (p = 0.047). There was no correlation between tumor ploidy pattern and location. In univariate analysis tumor growth through the serosal wall was predictive of poor survival (p = 0.003).

CONCLUSIONS

DNA ploidy is an independent prognostic indicator for cancer-specific survival in gastric cancer.

DNA ploidy and biologic aggressiveness of gastric adenocarcinoma in Chinese

The mortality rate of gastric cancer in the Chinese population has reached a plateau. The main prognostic factor for gastric adenocarcinoma is recognized as tumor stage. Recently, abnormalities in DNA content have been considered as a new prognostic factor. Whether abnormal DNA content can be used as a prognostic tool for Chinese patients with gastric cancer is unknown. To investigate this relation DNA ploidy and prognosis of gastric cancer patients were studied using paraffin-embedded specimens. A group of 104 newly diagnosed and surgically resected gastric cancer specimens obtained from January 1984 to December 1986 were examined for DNA content by flow cytometry. The quality of flow cytometry was acceptable with a mean coefficient of variance of 5.45. The results showed that 38 cases (36.5%) had DNA aneuploidy; 42 cases had metastatic lymph nodes with enough tumor cells, and 31.0% of these cases had DNA aneuploidy. DNA aneuploidy of primary tumors was correlated to lymph node metastasis and patient's age, whereas DNA aneuploidy of metastatic lymph nodes was significantly correlated to the serosal invasion of the gastric wall at the primary site. The important parameters for prognosis were curability of surgical resection, serosal invasion, tumor size, and distant metastasis. DNA aneuploidy of both primary tumors or metastatic lymph nodes appeared to be unrelated to the prognosis of gastric adenocarcinoma in Chinese patients. We therefore propose that DNA aneuploidy of gastric cancer is associated with tumor growth but not biologic aggressiveness.