Protein kinase C delta enhances the diagnostic performance of hepatocellular carcinoma

BACKGROUND

The conventional markers for hepatocellular carcinoma (HCC), α-fetoprotein (AFP) and des-γ-carboxy prothrombin (DCP), have several limitations; both have low sensitivity in patients with early-stage HCC; low sensitivity for AFP with HCC after eliminating hepatitis C virus (HCV); low specificity for DCP in patients with non-viral HCC, which is increasing worldwide; low specificity for AFP in patients with liver injury; and low specificity for DCP in patients treated with warfarin. To overcome these issues, the identification of novel biomarkers is an unmet need.

OBJECTIVE

This study aimed to assess the usefulness of serum protein kinase C delta (PKCδ) for detecting these HCCs.

METHODS

PKCδ levels were measured using a sandwich enzyme-linked immunosorbent assay in 363 chronic liver disease (CLD) patients with and without HCC.

RESULTS

In both viral and non-viral CLD, PKCδ can detect HCCs with high sensitivity and specificity, particularly in the very early stages. Notably, the value and sensitivity of PKCδ were not modified by HCV elimination status. Liver injury and warfarin administration, which are known to cause false-positive results for conventional markers, did not modify PKCδ levels.

CONCLUSIONS

PKCδ is an enhanced biomarker for the diagnosis of HCC that compensates for the drawbacks of conventional markers.

Extended-Synaptotagmin 1 Enhances Liver Cancer Progression Mediated by the Unconventional Secretion of Cytosolic Proteins

Extended-synaptotagmin 1 (E-Syt1) is an endoplasmic reticulum membrane protein that is involved in cellular lipid transport. Our previous study identified E-Syt1 as a key factor for the unconventional protein secretion of cytoplasmic proteins in liver cancer, such as protein kinase C delta (PKCδ); however, it is unclear whether E-Syt1 is involved in tumorigenesis. Here, we showed that E-Syt1 contributes to the tumorigenic potential of liver cancer cells. E-Syt1 depletion significantly suppressed the proliferation of liver cancer cell lines. Database analysis revealed that E-Syt1 expression is a prognostic factor for hepatocellular carcinoma (HCC). Immunoblot analysis and cell-based extracellular HiBiT assays showed that E-Syt1 was required for the unconventional secretion of PKCδ in liver cancer cells. Furthermore, deficiency of E-Syt1 suppressed the activation of insulin-like growth factor 1 receptor (IGF1R) and extracellular-signal-related kinase 1/2 (Erk1/2), both of which are signaling pathways mediated by extracellular PKCδ. Three-dimensional sphere formation and xenograft model analysis revealed that E-Syt1 knockout significantly decreased tumorigenesis in liver cancer cells. These results provide evidence that E-Syt1 is critical for oncogenesis and is a therapeutic target for liver cancer.

Acquisition of G₀ state by CD34-positive cord blood cells after bone marrow transplantation

OBJECTIVE

Hematopoietic stem cells are kept in a quiescent state in the hypoxic area of the bone marrow, which is essential for hematopoietic stem cell maintenance. However, when and how hematopoietic stem cells acquire their hypoxic state and maintain quiescence has not been fully elucidated. The aim of this study was to understand this process in human hematopoietic stem cells after bone marrow transplantation.

MATERIALS AND METHODS

Human CD34-positive cord blood cells were transplanted into nonobese diabetic/severe combined immunodeficient interleukin-2 receptor γ chain knockout mice. Cell cycle and hypoxia assay analyses were performed, to identify changes in the characteristics of human hematopoietic stem cells following transplantation. Quantitative real-time reverse transcription polymerase chain reaction analysis was used to analyze the transcriptional changes accompanying this transition.

RESULTS

Engrafted primitive lineage-negative CD34-positive CD38-negative cells acquired hypoxic state and quiescence in the recipient bone marrow between 4 and 8 weeks, and between 8 and 12 weeks after transplantation, respectively. During 4 and 8 weeks after transplantation, changes in the transcription levels of G₀ regulatory factors, such as CCNC and RBL1, and stem cell regulators, such as Flt3, were also seen, which may be related to the characteristic changes in the cell cycle or oxygenation state.

CONCLUSIONS

Behavioral changes of hematopoietic stem cells in their cell cycle and oxygenation state during and after bone marrow engraftment may provide insights into hematopoietic stem cell regulation, mediating the improvement of clinical hematopoietic stem cell transplantation protocols and the eradication of leukemia stem cells.

[Evaluation of midazolam premedication for preoperative anxiolysis]

To evaluate the anxiolysis property of midazolam, 60 patients undergoing minor gynecological surgery were given midazolam 0 mg (n = 20), 2.5 mg (n = 20) or 4 mg (n = 20) intramuscularly as premedication 1 h before their entrance to operating theater. The degree of anxiety was evaluated objectively using the State-Trait Anxiety Inventory (STAI). STAI test was performed twice: on the day before operation and 1 h after receiving preanesthetic premedication. In only midazolam 4 mg group, anxiety was reduced significantly in the operating room compared to the day before operation. It is concluded that midazolam (4 mg) is suitable to reduce the preoperative anxiety in patients who are to undergo minor gynecological surgery.

Vaccination of children in Japan

The coverage rates of six vaccines (BCG, polio, DPT, measles, mumps and varicella) and the prevalence of these diseases in Japan were investigated. It was found that 82.2% of children had been inoculated with BCG before their first birthday, and 85.4% were given two doses of polio vaccine before their second birthday. The high acceptance rates of these vaccines seem to be attributable to mass inoculations at health centers. On the other hand, the median age when the first dose of DPT vaccine was given was as late as 22 months. Mass administration of this vaccine during infancy should be performed since about one-quarter of the patients with diphtheria, pertussis or tetanus were less than one year old. The cumulative percentage for measles inoculation failed to reach 60% by the second birthday. Considering that the incidence of measles has not yet been satisfactory lowered and that infants under 23 months of age account for about one-half of this incidence, more children less than 18 months old should be immunized. The ineffective rate of varicella vaccine was found to be 18.2%, although reestimation of its effectiveness may be necessary.