The human tissue kallikrein family of serine proteases (hK1-hK15 encoded by the genes KLK1-KLK15) is involved in several cancer-related processes. Accumulating evidence suggests that certain tissue kallikreins are part of an enzymatic cascade pathway that is activated in ovarian cancer and other malignant diseases. In the present study, OV-MZ-6 ovarian cancer cells were stably co-transfected with plasmids expressing hK4, hK5, hK6, and hK7. These cells displayed similar proliferative capacity as the vector-transfected control cells (which do not express any of the four tissue kallikreins), but showed significantly increased invasive behavior in an in vitro Matrigel invasion assay (p<0.01; Mann-Whitney U-test). For in vivo analysis, the cancer cells were inoculated into the peritoneum of nude mice. Simultaneous expression of hK4, hK5, hK6, and hK7 resulted in a remarkable 92% mean increase in tumor burden compared to the vector-control cell line. Five out of 14 mice in the 'tissue kallikrein overexpressing' group displayed a tumor/situs ratio greater than 0.198, while this weight limit was not exceeded at all in the vector control group consisting of 13 mice (p=0.017; chi2 test). Our results strongly support the view that tumor-associated overexpression of tissue kallikreins contributes to ovarian cancer progression.

Recent evidence suggests that many tissue kallikreins are implicated in carcinogenesis. Kallikrein 8 (KLK8) plays a role in the physiology of the central nervous system. Kallikrein 7 (KLK7) takes part in skin desquamation. Both show altered expression in ovarian and breast cancer. In this study, we examined the level of mRNA expression of the KLK7 and KLK8 genes in 73 intracranial tumors using qualitative RT-PCR. The results were correlated with clinical and histomorphological variables and patient outcome. The expression of both genes was also examined in the brain cancer cell lines U-251 MG, D54 and SH-SY5Y and the invasive capacity of glioblastoma cells U-251 MG overexpressing hK7 or hK8 was also investigated in an in vitro Matrigel assay. Follow-up analysis revealed that expression of KLK7 mRNA was associated with shorter overall survival (OS) compared to patients with no KLK7 expression, as determined by Cox proportional hazard regression analysis. Overexpression of hK7 protein by cultivated brain tumor cells significantly enhanced the invasive potential in the Matrigel invasion assay, in contrast to cells overexpressing hK8 protein. Our data suggest that hK7 protein overexpression is associated with a more aggressive phenotype in brain cancer cells.

Background:The human tissue kallikrein gene family (KLK1 to KLK15) encodes a group of 15 serine proteases (hK1 to hK15), several of which have been implicated in cancer-related processes. Methods: We established a specific quantitative reverse transcription-PCR assay for full-length KLK7 mRNA that excluded amplification of the exon 2 deletion splice variant (the latter does not encode a functional protease), and evaluated full-length KLK7 mRNA expression [normalized to human glucose-6-phosphate dehydrogenase (h-G6PDH)] in tumor tissue specimens from 155 breast cancer patients. Results: High KLK7 mRNA expression (continuous) was significantly associated with a better patient outcome according to both univariate (P ‫؍‬ 0.005) and multivariate (P ‫؍‬ 0.046) Cox survival analysis. Separation of patients by optimized dichotomization revealed a significantly better prognosis for patients with high KLK7 mRNA status (n ‫؍‬ 89) compared with patients

SummaryHuman tissue kallikrein-related peptidases are a family of 15 secreted serine proteases, located at chromosome 19q13.4. Most of them have been reported to be potential biomarkers for several carcinomas and other diseases. Human tissue kallikrein-related peptidase 7 (KLK7) has been purified from human stratum corneum and resembles a chymotryptic endopeptidase originally called stratum corneum chymotryptic enzyme (SCCE). In this study, we examined for the first time, the prognostic value of KLK7 mRNA expression, using a semi-quantitative RT-PCR method, in 105 colorectal cancer tissues for 54 of which, paired normal colonic mucosa were available. Furthermore, we analysed the expression of KLK7 in 10 adenomas, in 18 biopsies of inflamed colon mucosa, as well as in 22 human cancer cell lines of various origin, four of them being of colon. A defined number of colon cancer samples were also examined by immunohisto-chemistry. KLK7 expression was higher in cancerous than in normal tissues. Less differentiated tumors of more advanced stage showed higher KLK7 expression. Follow-up analysis revealed that KLK7 was significantly associated with shorter overall survival (OS) and disease-free survival (DFS). In addition, selected colon cancer samples highly expressing KLK7 gene, showed intense immunohistochemical staining for KLK7, enhancing RTPCR results. Present data suggest that KLK7 gene is up-regulated in colon cancer and its expression predicts poor prognosis for colon cancer patients.

The human tissue kallikrein family encompasses 15 serine proteases. Most of the tissue kallikrein genes (KLK1-15) or proteins (hK1-15) have been found to be either under-or overexpressed in certain carcinomas, especially in breast, prostate, testicular and ovarian cancer. In ovarian cancer tissue, several tissue kallikreins are strongly over-or even de novo expressed, compared to normal ovarian tissue. This may indicate that these tissue kallikreins participate in an enzymatic cascade pathway which is strongly activated in ovarian cancer. In the present study, full length cDNAs encoding hK4, hK5, hK6, and hK7 were amplified from ovarian cancer tissue and cloned into the eukaryotic expression vector pRcRSV. OV-MZ-6 ovarian cancer cells, which do not express any of the four tissue kallikreins, were stably co-transfected with these plasmids resulting in the tumor cell line OV-KLK4+5+6+7. Applying sensitive ELISA formats for hK4, hK5, hK6 and hK7, we demonstrated that the stably transfected OV-KLK4+5+6+7 cell line secreted detectable amounts of the respective tissue kallikreins into the medium, ranging from about 0.5 to 20 ng/ml after growth in culture for 48 h. OV-KLK4+5+6+7 cells displayed similar proliferative capacity as the vector-transfected control cells (OV-RSV), but showed a significantly increased invasive behavior in the in vitro Matrigel invasion assay (p<0.01; Mann-Whitney U-test). For in vivo analysis, cells expressing the four tissue kallikreins were inoculated into the peritoneum of nude mice. Simultaneous expression of hK4, hK5, hK6, and hK7 resulted in a remarkable 92% mean increase of tumor burden compared to the vector-control cell line. Five out of 14 mice in the "tissue kallikrein overexpressing" group displayed a tumor/situs ratio of greater than 0.198, while this weight limit was not at all exceeded in the vector control group consisting of 13 mice (p=0.017; chi-square-test). Our results strongly support the view that tumor-associated overexpression of tissue kallikreins contributes to ovarian cancer progression.

As electrified vehicles become widely accepted, consumers expect the characteristics to be similar to those with a conventional, internal-combustion engine. Among these is the ability to ‘refuel’ quickly. For example, current lithium-ion battery technology takes an hour or more to recharge (refuel) whereas a conventional car can take 5 minutes or less. Some work has been does to understand the electrical effect fast charging lithium-ion cells has. However, no one understands what faster charging does to internal cell components. We cycled commercially-available 18650 cells at four different charge C-rates (0.7, 2, 4, 6) and two different charge-returned windows (40% and 100%); the discharge rate was C/3. The cells were opened and both electrodes as well as separator were analysed in an argon-environment glove box using a range of surface-sensitive, analytical techniques. The binder material at the negative electrode decomposed at higher C-rates causing delamination from the copper current collector. Surprisingly, cells cycled within a smaller charge-returned window completely delaminated irrespective of C-rate, suggesting there are at least two different mechanisms responsible for electrode delamination in the cells. Analysis of surface film chemistry and thickness showed a dependence on C-rate. Cells cycled at higher C-rates had a thicker surface film and a more complex chemistry. Gel permeation - liquid chromatography showed that the surface film of the cells was extremely complex, with a large range of molecular weights (MW). As the C-rate increased, the average MW of the oligomers from the surface film also increased. These findings indicate that an increased charging rate affects the negative electrodes surface film and its adhesion to the current collector. Although a smaller SoC window caused less resistance increase and capacity losses in 18650 cells it was detrimental to the lamination properties. This could have significant implications for unconstrained pouch cells.

The family of human tissue kallikreins is a subgroup of serine proteases that has recently been identified. The family consists of 15 members, many of which exhibit an altered expression in various types of cancer, such as prostate, ovarian and breast cancer. Therefore, kallikreins may have a potential role as markers for malignancy. Human kallikrein 5 (KLK5, HSCTE) and 7 (KLK7, HSCCE) are members of the kallikrein family that have been identified from a keratinocyte library. These serine proteases are implicated in the degradation of intercellular cohesive structures in the outermost layer of the skin and contribute to the cell shedding process at the skin surface. It has been proposed that hK5 may act as activator of hK7 in the above process. KLK5 has been shown to be differentially expressed in a variety of endocrine tumors including ovarian, breast and prostate cancer. KLK7 is differentially expressed in ovarian and breast cancer and may be a potent biomarker for these diseases. The purpose of our study was to examine the possible co-expression of the two genes in breast cancer. We developed RT-PCR methods in order to selectively amplify the full length splice variants of KLK5 and KLK7. The mRNA expression of the two genes was examined in a group of 80 breast cancer samples. Actin was used as a house-keeping gene. The PCR products were sequenced in order to verify their identity. The results were correlated to other clinical and histopathological variables as well as to patient outcome. KLK5 was found to be expressed in 30/80 (37,5%) of breast cancer tissues and KLK7 in 26/80 (32,5%). KLK7 was significantly (p=0,04) more frequently expressed in samples that were positive for KLK5 expression. KLK5 expression was more frequent in tumors with low levels of estrogen receptors (p=0,04) and progesterone receptors (p=0,005). KLK7 expression was more frequent in tumors with low levels of estrogen receptors (p=0,04). KLK7 expression was also associated with shorter overall survival. Our results are in agreement with the hypothesis that there is an interplay between KLK5 and KLK7 expression. It is also suggested by the statistical analysis that KLK5 and KLK7 expression is correlated with hormone-independent, and thus, poor prognosis tumors.