Prognostic Value of Cytokeratin-Positive Bone Marrow Cells of Gastric Cancer Patients

The Progress and Prospects of Putative Biomarkers for Liver Cancer Stem Cells in Hepatocellular Carcinoma

Accumulating evidence suggests that hepatocellular carcinoma (HCC) is organized by liver cancer stem cells (LCSCs), which are a subset of cells with “stem-like” characteristics. Identification of the LCSCs is a fundamental and important problem in HCC research. LCSCs have been investigated by various stem cell biomarkers. There is still lack of consensus regarding the existence of a “global” marker for LCSCs in HCC. In this review article, we summarize the progress and prospects of putative biomarkers for LCSCs in the past decades, which is essential to develop future therapies targeting CSCs and to predict prognosis and curative effect of these therapies.

Expression of cancer stem cell biomarkers as a tool for a correct therapeutic approach to hepatocellular carcinoma

Liver cancer is the fifth most commonly diagnosed malignancy and the second most frequent cause of cancer death in men worldwide. Amongst liver cancers, hepatocellular carcinoma (HCC) represents the major histological subtype and it is one of the most common malignant human tumors worldwide. Research into the molecular biology of hepatocarcinogenesis has identified several biomarkers, which could provide additional informations in order to better understand the biology of HCC. A large number of biomarkers have been shown to have potential predictive significance and a wide variety of molecular markers have been proven to be excellent diagnostic tools for HCC but it is difficult to characterize HCC with a single biomarker. Thus, signatures of a combination of biomarkers may be more valuable for the diagnosis, staging and prognosis of HCC. Specifically, a correlation of HCC-CSCs phenotype to specific hepatic cancer subtypes and to specific clinical and pathological features has not yet been reported in human liver tumors. In this view we will first discuss the possible sources of liver stem cells and their relation with liver cancer development and we will secondly focus on the prognostic significance of clinical and pathological features of HCC.

Disseminated tumor cells in bone marrow of gastric cancer patients: correlation with tumor hypoxia and clinical relevance

Aim. The evaluation of the clinical relevance of disseminated tumor cells (DTCs) in bone marrow (BM) of patients with gastric cancer (GC) and their association with primary tumor hypoxia. Patients and Methods. 89 resected specimens were used. DTCs were detected using immunocytochemistry, the level of tumor hypoxia using NMR spectroscopy, CD68, CD34, VEGF, and VEGFR-1 (Flt-1) expression using immunohistochemistry, and MMP-2 and MMP-9 activity using zymography. Results. DTCs were detected in 51.4% of GC patients with M₀. There was significant correlation between frequency of DTCs in BM and level of tumor hypoxia (P < 0.024). DTCs presence was accompanied with Flt-1 positivity of BM. The correlation between DTCs and tumor VEGF expression in patients with M₀ was shown (P < 0.0248). Activity of MMP-2 and MMP-9 in BM was linked with DTCs in patients with M₀ (P < 0.05). Overall survival (OS) of patients with M₀ and DTCs was shorter than that of patients without DTCs (patients in both groups were operated only) (P = 0.0497). Conclusion. Appearance of DTCs correlates with hypoxia level in primary tumors. Detection of DTCs in GC patients may be relevant indicator for adjuvant chemotherapy using.

Detection of disseminated tumor cells in bone marrow of gastric cancer using magnetic activated cell sorting and fluorescent activated cell sorting

BACKGROUND AND AIM

Magnetic activated cell sorting (MACS) and fluorescent activated cell sorting (FACS) were employed to enrich and detect the gastric cancer cells from a cell line in a model system, and to enrich and detect disseminated tumor cells (DTCs) from bone marrow (BM) of patients with gastric cancer.

METHODS

Fifteen patients with benign gastric lesions and 35 patients with gastric cancer who received curative operations between December 2002 and June 2003 were selected. Mononuclear cells were separated from their BM. Cells from cell line OCUM-2M were seeded with 10-grade ratio into mononuclear cells from patients with benign gastric lesion. After labeling by MACS minibeads conjugated with cytokeratin (CK) 7/8 antibodies, anti-CK-fluorescein isothiocyanate (FITC), and anti-CD45-perdinin chlorophyll protein (PerCP), the samples were enriched twice using an MS+/RS+ positive separation column. The FACS analysis was conducted on these samples before and after MACS enrichment. The results were analyzed using clinopathological parameters.

RESULTS

Disseminated tumor cells were detected in the BM of 25 (71.43%) patients with gastric cancer. The frequencies of DTCs were 1.38 x 10(-8)-2.40 x 10(-5), 2.19 x 10(-7)-3.70 x 10(-5), 4.01 x 10(-6)-8.57 x 10(-5) in patients with well, moderately, and poorly differentiated carcinoma, respectively (P = 0.026). Disseminated tumor cells in BM had close correlation with tumor tumor-node-metastasis (TNM) stage (P = 0.034) and cancer-free survival (P = 0.035).

CONCLUSION

Disseminated tumor cells are very common in the BM of gastric cancer patients. Poor histological differentiation and more advanced TNM stage have more DTCs in the BM of gastric cancer patients. Patients with DTCs tend to have a poor prognosis.

Cytokeratin 10 and cytokeratin 19: predictive markers for poor prognosis in hepatocellular carcinoma patients after curative resection

PURPOSE

Cytokeratin 10 (CK10) was found to be expressed differently in human hepatocellular carcinoma (HCC) cell lines with different metastatic potentials in our previous research. The aim of this study was to assess the value of CK10 alone or in combination with cytokeratin 19 (CK19) in predicting tumor recurrence after curative resection in HCC patients.

EXPERIMENTAL DESIGN

CK10 expression in stepwise metastatic HCC cell lines and tumor tissues from 50 HCC patients was investigated using immunofluorescence assay, quantitative real-time reverse transcription-PCR, and Western blot analyses. Tumor tissue microarrays of 300 HCC patients who underwent curative resection between 1997 and 2000 were used to detect the expressions of CK10 and CK19. Clinicopathologic data for these patients were evaluated. The prognostic significance was assessed using Kaplan-Meier survival estimates and log-rank tests.

RESULTS

CK10 was overexpressed in the high metastatic HCC cell line and in tumor tissues of recurrent patients. Both univariate and multivariate analyses revealed that CK10 was a significant predictor for overall survival (OS) and disease-free survival, and that CK19 was a significant predictor for OS. CK10 expression was correlated with poor prognosis regardless of alpha-fetoprotein, tumor-node-metastasis stage, and vascular invasion. The 7-year OS and disease-free survival rates in CK10+ and/or CK19+ patients were 30.0% and 37.6%, respectively, which were significantly lower than that of CK10-/CK19- patients (56.1% and 60.0%, respectively; P < 0.001).

CONCLUSION

CK10 is associated with HCC invasiveness. CK10 alone, or in combination with CK19, can be a novel predictor for poor prognosis of HCC patients after curative resection.

Markers of tumour angiogenesis and tumour cells in bone marrow in gastric cancer patients

AIMS

Vascular endothelial growth factors VEGF-A, VEGF-C and VEGF-D are considered to be potentially angiogenetic and lymphangiogenetic. "Minimal residual disease" is responsible for cancer progression and recurrence. In this study, we investigated the relation between expressions of VEGF-A, VEGF-C and VEGF-D in gastric cancer tissue and the presence of tumour cells in bone marrow.

METHODS

A total of 50 resected primary gastric adenocarcinomas, 44 non-cancerous gastric mucosa and 36 lymph node metastases were analyzed by immunohistochemistry for VEGF-A, VEGF-C and VEGF-D. The specimens used were drawn from a previous study cohort, where the presence of ITC in bone marrow was confirmed with immunohistochemical assay with cytokeratin (CK)-18.

RESULTS

The levels of expression of VEGF-A, VEGF-C and VEGF-D were highest in tumour (p < 0.001), and the level in lymph node metastases was significantly higher (p < 0.01) than in mucosa. The expression of VEGF-A was correlated significantly with venous tumour invasion (p < 0.05) and the presence of tumour cells in bone marrow (p < 0.05). Tumours expressing high levels of VEGF-D showed significantly advanced stages of tumour infiltration (p < 0.05) and lymph node metastasis (p < 0.01).

CONCLUSIONS

VEGF-A is a significant marker for the presence of tumour cells in the bone marrow of gastric cancer patients. Our results confirm VEGF-D as a predictor for the lymphatic spread of tumour cells. Therefore, the route of metastatic spread of gastric cancer could be determined, at least in part, by the profile of VEGF family members expressed in the primary tumour of gastric cancer patients.

The effects of preoperative chemotherapy on isolated tumour cells in the blood and bone marrow of gastric cancer patients

Recent studies in breast cancer suggest that monitoring the isolated tumour cells (ITC) may be used as a surrogate marker to evaluate the efficacy of systemic chemotherapy. In the present study, we have investigated the effects of preoperative chemotherapy on ITC in the blood and bone marrow of patients with potentially resectable gastric cancer. After sorting out the CD45-positive cells, the presence of ITC defined as cytokeratin-positive cells was examined before and after preoperative chemotherapy. The patients received two courses of preoperative chemotherapy with cisplatin (100 mg m⁻², day 1) and 5-fluorouracil (1000 mg m⁻², days 1–5), administered every 28 days. Fourteen of 32 (44%) patients initially diagnosed with ITC in blood and/or bone marrow were found to be negative (responders) after preoperative chemotherapy (P<0.01). The incidence of ITC in bone marrow was also significantly (P<0.01) reduced from 97 (31 of 32) to 53% (17 of 32). The difference between patients positive for ITC in the blood before (n=7, 22%) and after (n=5, 16%) chemotherapy was statistically insignificant. The overall 3-year survival rates were 32 and 49% in the responders and non-responders, respectively (P=0.683). These data indicate that preoperative chemotherapy can reduce the incidence of ITC in patients with gastric cancer.

[Minimal residual tumor in gastrointestinal carcinoma. Relevance to prognosis and oncologic surgical consequences]

Isolated tumor cells as a consequence of minimal residual disease are often not detectable by routine diagnostic procedures. However, before or after surgery, isolated tumor cells in lymph nodes, the peritoneal cavity, blood, or bone marrow can frequently be identified by immunohistochemical or molecular methods. Failure to reveal the presence of such cells results in under-staging of tumor patients and may constitute the source of unexpected tumor recurrence after radical surgery. These facts emphasize the importance of isolated tumor cells at least as a surrogate marker. The frequency of appearance of isolated tumor cells in different organ systems also depends on the type of primary tumor. Developments in modern detection methods have led to increasing sensitivity but at the expense of specificity. Isolated tumor cells demonstrate remarkable heterogeneity with respect to proliferative potential and tumorigenicity. This characteristic is also reflected by a striking variability in the expression of various genes conditioning the aforementioned biological behavior. Unfortunately there is also remarkable heterogeneity in methods used for sampling and processing patient material as well as for the enrichment and detection of isolated tumor cells. Despite the ongoing controversies concerning detection methods and biological significance of isolated tumor cells, several clinical trials providing data supporting the prognostic relevance of minimal residual disease should also be considered for gastrointestinal carcinoma. In future this finding should be integrated in the planning of trials in surgical oncology, and "minimal residual disease" should receive stronger attention as a stratification criterion in such clinical studies.