Three-Dimensional Structure of Novel Liver Cancer Biomarker Liver Cancer-Specific Serine Protease Inhibitor Kazal (LC-SPIK) and Its Performance in Clinical Diagnosis of Hepatocellular Carcinoma (HCC).

LC-SPIK is a liver cancer-specific isoform of Serine Protease Inhibitor Kazal and has been proposed as a new biomarker for the detection of HCC given its unique 3D structure, which differs from normal pancreatic SPIK. An ELISA technology based on its unique structure was developed to use LC-SPIK as an effective biomarker for the clinical diagnosis of HCC. AFP, the most widely used biomarker for HCC surveillance currently, suffers from poor clinical performance, especially in the detection of early-stage HCC. In one case-control study, which included 164 HCC patients and 324 controls, LC-SPIK had an AUC of 0.87 compared to only 0.70 for AFP in distinguishing HCC from liver disease controls (cirrhosis, HBV/HCV). LC-SPIK also performed significantly better than AFP for the 81 patients with early-stage HCC (BCLC stage 0 and A), with an AUC of 0.85 compared to only 0.61 for AFP. Cirrhosis is the major risk factor for HCC; about 80% of patients with newly diagnosed HCC have preexisting cirrhosis. LC-SPIK's clinical performance was also studied in HCC patients with viral and non-viral cirrhosis, including cirrhosis caused by metabolic dysfunction-associated steatotic liver disease (MASLD) and alcoholic liver disease (ALD). In a total of 163 viral cirrhosis patients with 93 HCC patients (50 early-stage), LC-SPIK had an AUC of 0.85, while AFP had an AUC of 0.70. For patients with early-stage HCC, LC-SPIK had a similar AUC of 0.83, while AFP had an AUC of only 0.60. For 120 patients with nonviral cirrhosis, including 62 HCC (23 early-stage) patients, LC-SPIK had an AUC of 0.84, while AFP had an AUC of only 0.72. For the 23 patients with early-stage HCC, LC-SPIK had a similar AUC of 0.83, while the AUC for AFP decreased to 0.65. All these results suggest that LC-SPIK exhibits significantly better performance in the detection of HCC than AFP in all etiologies of liver diseases. In addition, LC-SPIK accurately detected the presence of HCC in 71-91% of HCC patients with false-negative AFP test results in viral-associated HCC and non-viral-associated HCC.

Liver Cancer-Specific Serine Protease Inhibitor Kazal Is a Potentially Novel Biomarker for the Early Detection of Hepatocellular Carcinoma.

INTRODUCTION: Liver cancer-secreted serine protease inhibitor Kazal (LC-SPIK) is a protein that is specifically elevated in cases of hepatocellular carcinoma (HCC). We assessed the performance of LC-SPIK in detecting HCC, including its early stages, in patients with cirrhosis, hepatitis B virus (HBV), and hepatitis C virus (HCV). METHODS: We enrolled 488 patients, including 164 HCC patients (81 early HCC) and 324 controls in a blinded, prospective, case-control study. Serum LC-SPIK levels were determined by an enzyme-linked immunosorbent assay-based assay. The performance of serum LC-SPIK and α-fetoprotein (AFP), including area under the curve (AUC), sensitivity, and specificity, are compared. The performance of LC-SPIK was evaluated in an independent validation cohort with 102 patients. RESULTS: In distinguishing all HCC patients from those with cirrhosis and chronic HBV/HCV, LC-SPIK had an AUC of 0.87, with 80% sensitivity and 90% specificity using a cutoff of 21.5 ng/mL. This is significantly higher than AFP, which had an AUC of 0.70 and 52% sensitivity and 86% specificity using a standard cutoff value of 20.0 ng/mL. For early-stage HCC (Barcelona Clinic Liver Cancer stage 0 and A), LC-SPIK had an AUC of 0.85, with 72% sensitivity and 90% specificity, compared with AFP, which had an AUC of 0.61, with 42% sensitivity and 86% specificity. In addition, LC-SPIK accurately detected the presence of HCC in more than 70% of HCC patients with false-negative AFP results. DISCUSSION: The study provided strong evidence that LC-SPIK detects HCC, including early-stage HCC, with high sensitivity and specificity, and might be useful for surveillance in cirrhotic and chronic HBV/HCV patients, who are at an elevated risk of developing HCC.

Role of the inflammatory protein serine protease inhibitor Kazal in preventing cytolytic granule granzyme A-mediated apoptosis.

Serine protease inhibitor Kazal (SPIK) is an inflammatory protein whose levels are elevated in numerous cancers. However, the role of this protein in cancer development is unknown. We have recently found that SPIK suppresses serine protease-dependent cell apoptosis. Here, we report that anti-SPIK antibodies can co-immmunoprecipitate serine protease granzyme A (GzmA), a cytolytic granule secreted by cytotoxic T lymphocytes and natural killer cells during immune surveillance, and that SPIK suppresses GzmA-induced cell apoptosis. Deletion studies show that the C3-C4 region of SPIK is critical for this suppression. These studies suggest that over-expression of SPIK may prevent GzmA-mediated immune-killing, thereby establishing the tolerance of cancer cells to the body's immune surveillance system. Suppression of over-expressed SPIK can restore the susceptibility of these cells to apoptotic death triggered by GzmA. This finding implies that it is possible to overcome tolerance of cancer cells to the body's immune surveillance system and restore the GzmA-mediated immune-killing by suppressing the over-expression of SPIK.

Multiplexed broadband beam steering system utilizing high speed MEMS mirrors.

We present a beam steering system based on micro-electromechanical systems technology that features high speed steering of multiple laser beams over a broad wavelength range. By utilizing high speed micromirrors with a broadband metallic coating, our system has the flexibility to simultaneously incorporate a wide range of wavelengths and multiple beams. We demonstrate reconfiguration of two independent beams at different wavelengths (780 and 635 nm) across a common 5x5 array with 4 micros settling time. Full simulation of the optical system provides insights on the scalability of the system. Such a system can provide a versatile tool for applications where fast laser multiplexing is necessary.

Tumor-associated protein SPIK/TATI suppresses serine protease dependent cell apoptosis.

Serine protease dependent cell apoptosis (SPDCA) is a recently described caspase independent innate apoptotic pathway. It differs from the traditional caspase dependent apoptotic pathway in that serine proteases, not caspases, are critical to the apoptotic process. The mechanism of SPDCA is still unclear and further investigation is needed to determine any role it may play in maintaining cellular homeostasis and development of disease. The current knowledge about this pathway is limited only to the inhibitory effects of some serine protease inhibitors. Synthetic agents such as pefabloc, AEBSF and TPCK can inhibit this apoptotic process in cultured cells. There is little known, however, about biologically active agents available in the cell which can inhibit SPDCA. Here, we show that over-expression of a cellular protein called serine protease inhibitor Kazal (SPIK/TATI/PSTI) results in a significant decrease in cell susceptibility to SPDCA, suggesting that SPIK is an apoptosis inhibitor suppressing this pathway of apoptosis. Previous work has associated SPIK and cancer development, indicating that this finding will help to open the doorway for further study on the mechanism of SPDCA and the role it may play in cancer development.

MEMS-based optical beam steering system for quantum information processing in two-dimensional atomic systems.

To provide scalability to quantum information processors utilizing trapped atoms or ions as quantum bits (qubits), the capability to address multiple individual qubits in a large array is needed. Microelectromechanical systems (MEMS) technology can be used to create a flexible and scalable optical system to direct the necessary laser beams to multiple qubit locations. We developed beam steering optics using controllable MEMS mirrors that enable one laser beam to address multiple qubit locations in a two-dimensional trap lattice. MEMS mirror settling times of approximately 10 micros were demonstrated, which allow for fast access time between qubits.