Side population cell fractions from hepatocellular carcinoma cell lines increased with tumor dedifferentiation, but lack characteristic features of cancer stem cells.

BACKGROUND AND AIM: Cancer stem cells (CSCs), a minority population with stem cell-like characteristics, play important roles in cancer development and progression. Putative CSC markers, such as CD13, CD90, CD133, and epithelial cell adhesion molecule (EpCAM), and side population (SP) technique are generally used in an attempt to isolate CSCs. We aimed to clarify the relationship between CSCs and clonal dedifferentiation in hepatocellular carcinoma (HCC). METHODS: We used a well-differentiated HCC cell line (HAK-1A) and a poorly differentiated HCC cell line (HAK-1B) established from a single nodule with histological heterogeneity. HAK-1B arose because of clonal dedifferentiation of HAK-1A. The SP cells and non-SP (NSP) cells were isolated from the two cell lines with a FACSAria II and used for the analyses. RESULTS: The SP cell fractions in HAK-1A and HAK-1B were 0.2% and 0.9%, respectively. CD90 or EpCAM was not expressed in either HAK-1A or HAK-1B, while CD13 and CD133 were expressed in HAK-1B alone. Although sphere forming ability, tumorigenicity, growth rate, and CD13 expression were higher in HAK-1B SP cells than HAK-1B NSP cells, there were no differences in drug resistance, colony forming ability, or cell cycle rates between HAK-1B SP and NSP cells, suggesting HAK-1B SP cells do not fulfill CSC criteria. CONCLUSIONS: Our findings suggested a possible relationship between the expression of CSC markers and clonal dedifferentiation. However, the complete features of CSC could not be identified in SP cells, and the concept of SP cells as a universal marker for CSC may not apply to HAK-1A and HAK-1B.

Clinicopathologic analysis of combined hepatocellular-cholangiocarcinoma according to the latest WHO classification.

Combined hepatocellular-cholangiocarcinoma comprises <1% of all liver carcinomas. The histogenesis of combined hepatocellular-cholangiocarcinoma has remained unclear for many years. However, recent advances in hepatic progenitor cell (HPC) investigations have provided new insights. The concept that combined hepatocellular-cholangiocarcinoma originates from HPCs is adopted in the chapter "combined hepatocellular-cholangiocarcinoma" of the latest World Health Organization (WHO) classification. In this study, we conducted clinicopathologic analysis of combined hepatocellular-cholangiocarcinoma according to the latest WHO classification. Fifty-four cases were included in this study. Pathologic diagnosis was made according to the WHO classification. When a tumor contained plural histologic patterns, predominant histologic pattern (≥50%) was defined. Minor histologic patterns were also appended. Immunohistochemical staining with biliary markers (CK7, CK19, and EMA), hepatocyte paraffin (HepPar)-1, HPC markers (CD56, c-kit, CD133, and EpCAM), and vimentin was performed. Forty-five and 50 patients were analyzed for progression-free survival and overall survival, respectively. Ten, 1, 32, and 11 cases were diagnosed as: combined hepatocellular-cholangiocarcinoma, classical type; combined hepatocellular-cholangiocarcinoma, stem cell features, typical subtype; combined hepatocellular-cholangiocarcinoma, stem cell features, intermediate cell subtype; and combined hepatocellular-cholangiocarcinoma, stem cell features, cholangiolocellular type, respectively. Combined hepatocellular-cholangiocarcinomas usually have high expression of biliary markers. CD56, c-kit, and EpCAM were expressed to various degrees in all combined hepatocellular-cholangiocarcinomas apart from the hepatocellular carcinoma component of combined hepatocellular-cholangiocarcinoma, classical type. The expression of CD133 and vimentin was observed only in combined hepatocellular-cholangiocarcinoma, stem cell features of intermediate cell subtype and cholangiolocellular subtype. The expression of CD133, EpCAM, and vimentin was significantly high in combined hepatocellular-cholangiocarcinoma, subtypes with stem cell features, especially cholangiolocellular subtype. Minor histologic patterns were significantly frequent in combined hepatocellular-cholangiocarcinoma, subtypes with stem cell features, compared with combined hepatocellular-cholangiocarcinoma, classical type. There was no significant difference in clinical outcome between each subtype. Combined hepatocellular-cholangiocarcinoma has wide histologic diversity and shows immunophenotypic expression of not only biliary markers but also HPC markers to various degrees, suggesting that the histogenesis of combined hepatocellular-cholangiocarcinoma could be strongly associated with HPCs. Our results pathologically validate the latest WHO classification of combined hepatocellular-cholangiocarcinoma. However, the complex mixture of histologic subtypes has presented a challenge to the classification of combined hepatocellular-cholangiocarcinoma. Further study should be conducted using a large cohort to support this classification.

Treatment outcome in patients with stage III breast cancer treated with neoadjuvant chemotherapy.

Despite the good responses of patients (pts) with stage III breast cancer to neoadjuvant chemotherapy (NAC), most eventually relapse and have a poor prognosis. We investigated the prognostic indicators in pts with stage III breast cancer treated with NAC, using epirubicin and/or docetaxel. A total of 22 women with stage III breast cancer underwent NAC between January 2005 and May 2011. The regimens of NAC comprised ED (epirubicin 60 mg/m2 and docetaxel 60 mg/m2) in 10 cases, FEC (fluorouracil 500 mg/m2, epirubicin 75-100 mg/m2 and cyclophosphamide 500 mg/m2) in 10 cases and EC (epirubicin 60 mg/m2 and cyclophosphamide 600 mg/m2) in two cases. Following four cycles of each regimen, a further four cycles of D (docetaxel 70 mg/m2) were undertaken in nine cases. Subsequent to the completion of NAC and surgery, we assessed the clinicopathological results and performed prognostic analyses. Statistical analyses concerning disease-free survival (DFS) or overall survival (OS) were conducted by a Cox proportional hazard model. The median survival time was 66 months and there were 12 distant metastases and two local recurrences. Multivariate analyses showed the number of metastatic axillary lymph nodes (ALNs) [hazard ratio (HR), 1.079; P=0.023] was correlated with DFS, while the Ki-67 labeling index (HR, 1.109; P=0.042) and the number of meta-static ALNs (HR, 1.087; P=0.023) were correlated with OS. In conclusion, even if pts with stage III breast cancer show good responses to NAC using epirubicin and/or docetaxel, the majority eventually relapse and have a poor prognosis. The Ki-67 labeling index and the number of involved ALNs are suggested as prognostic indicators in stage III breast cancer.

FOXP3 expression in tumor cells and tumor-infiltrating lymphocytes is associated with breast cancer prognosis.

The forkhead box protein 3 (FOXP3) transcription factor is highly expressed in tumor cells as well as in regulatory T cells (Tregs). It plays a tumor-enhancing role in Tregs and suppresses carcinogenesis as a potent repressor of several oncogenes. The clinical prognostic value of FOXP3 expression has not yet been elucidated. In this study, immunohistochemistry was used to investigate the prognostic significance of FOXP3 expression in tumor cells and tumor-infiltrating lymphocytes (TILs) in breast cancer patients. Of the 100 tumor specimens obtained from primary invasive breast carcinoma, 63 and 57% were evaluated as FOXP3+ tumor cells and as being highly infiltrated by FOXP3+ lymphocytes, respectively. Although FOXP3 expression in tumor cells was of no prognostic significance, FOXP3+ lymphocytes were significantly associated with poor overall survival (OS) (n=98, log-rank test P=0.008). FOXP3 exhibited a heterogeneous subcellular localization in tumor cells (cytoplasm, 31%; nucleus, 26%; both, 6%) and, although cytoplasmic FOXP3 was associated with poor OS (P= 0.058), nuclear FOXP3 demonstrated a significant association with improved OS (P=0.016). Furthermore, when patients were grouped according to their expression of tumor cytoplasmic FOXP3 and lymphocyte FOXP3, there were notable differences in the Kaplan-Meier curves for OS (P<0.001), with a high infiltration of FOXP3+ lymphocytes accompanied by a cytoplasmic FOXP3+ tumor being the most detrimental phenotype. These findings indicated that FOXP3 expression in lymphocytes as well as in tumor cells may be a prognostic marker for breast cancer. FOXP3 in tumor cells may have distinct biological activities and prognostic values according to its localization, which may help establish appropriate cancer treatments.

Tumor-infiltrating lymphocytes are important pathologic predictors for neoadjuvant chemotherapy in patients with breast cancer.

Neoadjuvant chemotherapy or preoperative systemic therapy is increasingly considered for patients with operable breast cancer. Patients with breast cancer were examined for pathologic factors predictive of response to neoadjuvant chemotherapy, using an anthracycline-based regimen. For clinical histomorphology and biomarkers, factors were compared among 16 pathologically complete responses and 52 nonpathologically complete responses, using univariate analysis and multivariate regression analysis of principal components, using preneoadjuvant chemotherapy needle biopsy samples as follows: degree of tumor-infiltrating lymphocytes, histologic grade, biology-based tumor type (hormone receptors and HER2 [human epidermal growth factor receptor type 2]), age, clinical TNM stage, and TNM staging. In univariate analysis, high tumor-infiltrating lymphocyte, high histologic grade, and hormone receptors(-)/HER2(+) were significantly associated with pathologically complete responses (93.7%, P < .0001; 81.3%, P = .0206; 43.7%, P = .014, respectively). In multivariate principal component regression analysis, high tumor-infiltrating lymphocytes were the best independent predictor for pathologically complete responses (odds ratio, 4.7; confidence interval, 2.2-10.06; P < .0001). Among tumor-infiltrating lymphocytes and biology-based tumor types, patients with high tumor-infiltrating lymphocytes had pathologically complete responses more than nonpathologically complete responses, especially in the hormone receptors(-)/HER2(+) group. Among high tumor-infiltrating lymphocyte cases, T lymphocytes showed more predominant tendency than B lymphocytes in the pathologically complete responses cases, compared with nonpathologically complete responses cases. These findings indicate that high tumor-infiltrating lymphocytes are important predictors of pathologically complete responses to neoadjuvant chemotherapy, especially in the hormone receptors(-)/HER2(+) group.