Novel quantitative immunohistochemistry method using histone H3, family 3B as the internal reference standard for measuring human epidermal growth factor receptor 2 expression in breast cancer.

BACKGROUND: Immunohistochemistry (IHC) is an essential technique in surgical and clinical pathology for detecting diagnostic, prognostic, and predictive biomarkers for personalized cancer therapy. However, the lack of standardization and reference controls results in poor reproducibility, and a reliable tool for IHC quantification is urgently required. The objective of this study was to describe a novel approach in which H3F3B (histone H3, family 3B) can be used as an internal reference standard to quantify protein expression levels using IHC. METHODS: The authors enrolled 89 patients who had human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC). They used a novel IHC-based assay to measure protein expression using H3F3B as the internal reference standard. H3F3B was uniformly expressed at the protein level in all tumor regions in cancer tissues. HER2 expression levels were measured with the H-score using HALO software. RESULTS: Kaplan-Meier analysis indicated that, among patients who had HER2-positive BC in The Cancer Genome Atlas data set and the authors' data set, the subgroup with low HER2 expression had a significantly better prognosis than the subgroup with high HER2 expression. Furthermore, the authors observed that HER2 expression levels were precisely evaluated using the proposed method, which can classify patients who are at higher risk of HER2-positive BC to receive trastuzumab-based adjuvant therapy. Dual-color IHC with H3F3B is an excellent tool for internal and external quality control of HER2 expression assays. CONCLUSIONS: The proposed IHC-based quantification method accurately assesses HER2 expression levels and provides insights for predicting clinical prognosis in patients with HER2-positive BC who receive trastuzumab-based adjuvant therapy.

Clinical significance of ribosome production factor 2 homolog in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the third leading cause of cancer deaths worldwide. Dysregulation of ribosome biogenesis increases the risk of cancer. RPF2 (ribosome production factor 2 homolog), a member of the BRIX family, is involved in ribosome biogenesis. However, the biological functions of RPF2 in HCC remain unclear. This study aims to evaluate the function of RPF2 and its clinical significance in HCC. We collected 45 pairs of HCC/adjacent samples and 291 HCC samples. These samples were used to perform immunohistochemical analysis and western blot. Six cell lines were used to perform western blot, and two of cell lines, SMCC-7721 and SNU449, were subjected to CCK-8, wound healing and transwell assays. Immunofluorescence staining was executed in SMCC-7721 cells. The protein levels of RPF2 were higher in HCC tissues than in adjacent tissues. Immunofluorescence staining showed that the RPF2 protein was located in the nucleuses, especially the nucleolus. Furthermore, the immunohistochemical analysis showed that high expression levels of nuclear RPF2 correlated with poor prognosis, vascular invasion, liver cirrhosis and tumor size. Cell experiments showed that overexpression of RPF2 promoted cell proliferation, migration and invasion, while knockdown of RPF2 tended to show the opposite effect. This is the first report that RPF2 is involved in HCC progression. The levels of RPF2 were significantly high in HCC tumors and had a side effect on prognosis in HCC patients. RPF2 has the potential to be a useful marker for HCC.

A poor prognosis in human hepatocellular carcinoma is associated with low expression of DPP4

This study aimed to explore the prognostic role of dipeptidyl peptidase 4 (DPP4) expression in hepatocellular carcinoma (HCC). DPP4 expression was measured in formalin-fixed paraffin-embedded specimens that were gathered from 327 HCC patients. Immunohistochemistry analyses were utilized to examine DPP4 expression characteristics and prognostic values (overall survival (OS) and time to recurrence) of DDP4 in HCC tissues. In addition, a patient-derived xenograft (PDX) model was used to assess the correlation between DPP4 expression and tumor growth in vivo. DPP4 was expressed in low levels in HCC tissues in contrast to paired peritumoral tissues (38 cases were down-regulated in a total of 59 cases, 64.4%. P=0.0202). DPP4 expression was significantly correlated with TNM stage (P=0.038), tumor number (P=0.035), and vascular invasion (P=0.024), and significantly reduced in patients who were in TNM stages II and III-V, with multiple tumors, and with microvascular invasion compared to patients with TNM stage I, single tumor, and no microvascular invasion. Notably, HCC tissues with low expression of DPP4 had poor OS (P=0.016) compared with HCC tissues with high expression of DPP4, and results from PDX model showed that tumor growth was significantly faster in HCC patients that lowly expressed DPP4 compared to those with highly expressed DPP4. Our findings suggested that low levels of DPP4 could impact the aggressiveness of HCC and contribute to a poor prognosis.