Expression of cysteine peptidase cathepsin L and its inhibitors stefins A and B in relation to tumorigenicity of breast cancer cell lines

Zajc, Irena; Sever, Natasa; Bervar, Aleš; Lah, Tamara T.

doi:10.1016/s0304-3835(02)00452-4

Cited by 53 publications

(41 citation statements)

References 10 publications

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“…This balance may be altered upon cathepsin L overexpression. In contrast, MDA-MB-435 cells express relatively low levels of endogenous cathepsin L inhibitors (36,37), and hence proheparanase is readily processed and activated by these cells. Altogether, our results indicate that cathepsin L is the principal and most likely the sole enzyme responsible for processing and activation of proheparanase.…”

Section: Discussionmentioning

confidence: 95%

“…By contrast, MCF-7 cells overexpressing the 65-kDa proenzyme alone, exhibited a very low heparanase enzymatic activity. Interestingly, MCF-7 cells exhibit a low cathepsin L activity primarily due to their high content of endogenous cathepsin L inhibitors (36,37). This balance may be altered upon cathepsin L overexpression.…”

Section: Discussionmentioning

confidence: 99%

“…We next tested whether the high level of cathepsin L activity in MDA-MB-435 cells (36,37) is responsible for a more effective processing and generation of active heparanase in these cells than in MCF-7 cells. For this purpose, MCF-7 cells were transiently doubly transfected with vectors encoding for heparanase and cathepsin L, and compared with cells doubly transfected with heparanase and control empty vector.…”

Section: Knockdown Of Cathepsin L Markedly Suppresses Proheparanasementioning

confidence: 99%

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Cathepsin L Is Responsible for Processing and Activation of Proheparanase through Multiple Cleavages of a Linker Segment

Abboud-Jarrous

Atzmon

Peretz

et al. 2008

Journal of Biological Chemistry

157

125

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Heparanase is an endo-␤-D-glucuronidase that degrades heparan sulfate in the extracellular matrix and on the cell surface. Human proheparanase is produced as a latent protein of 543 amino acids whose activation involves excision of an internal linker segment (Ser 110 -Gln 157 ), yielding the active heterodimer composed of 8-and 50-kDa subunits. Applying cathepsin L knock-out tissues and cultured fibroblasts, as well as cathepsin L gene silencing and overexpression strategies, we demonstrate, for the first time, that removal of the linker peptide and conversion of proheparanase into its active 8 ؉ 50-kDa form is brought about predominantly by cathepsin L. Excision of a 10-amino acid peptide located at the C terminus of the linker segment between two functional cathepsin L cleavage sites (Y156Q and Y146Q) was critical for activation of proheparanase. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry demonstrates that the entire linker segment is susceptible to multiple endocleavages by cathepsin L, generating small peptides. Mass spectrometry demonstrated further that an active 8-kDa subunit can be generated by several alternative adjacent endocleavages, yielding the precise 8-kDa subunit and/or slightly elongated forms. Altogether, the mode of action presented here demonstrates that processing and activation of proheparanase can be brought about solely by cathepsin L. The critical involvement of cathepsin L in proheparanase processing and activation offers new strategies for inhibiting the prometastatic, proangiogenic, and proinflammatory activities of heparanase.

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Section: Discussionmentioning

confidence: 95%

Section: Discussionmentioning

confidence: 99%

Section: Knockdown Of Cathepsin L Markedly Suppresses Proheparanasementioning

confidence: 99%

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Cathepsin L Is Responsible for Processing and Activation of Proheparanase through Multiple Cleavages of a Linker Segment

Abboud-Jarrous

Atzmon

Peretz

et al. 2008

Journal of Biological Chemistry

157

125

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“…Stefin A is the major cysteine protease inhibitor (CPI) that has been associated most often with malignant progression. More specifically, a decrease in the level of stefin A has been demonstrated in malignant epithelial tumors such as human uterine portico, skin, lung, esophagus, Breast, Prostate and cervix (5)(6)(7)(8)(9)(10)(11). More compelling evidence demonstrated continual decrease in the level of stefin A mRNA during the progression of murine skin papillomas to carcinoma (12).…”

Section: Introductionmentioning

confidence: 99%

Functional expression of recombinant human stefin A in mammalian and bacterial cells

Calkins

Dosescu

Day

et al. 2007

Protein Expression and Purification

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Recombinant human cysteine protease inhibitor, stefin A, was expressed in both E. coli and BSC-1 monkey kidney cells utilizing pET and recombinant Vaccinia virus systems, respectively. The expressed protein was purified and analyzed by SDS-PAGE and western blot analysis utilizing a polyclonal antibody against rat cystatin α. In both cases the purified protein appeared as a single band corresponding to the molecular weight of stefin A (~10 kDa). Viability of the expressed stefin A was determined by the inhibition of the plant cysteine protease, papain. Recombinant human stefin A expressed in both E. coli and BSC-1 cells was shown to almost completely inhibit papain. The expression of a fully functional recombinant human stefin A in the bacterial system provides a highly efficient tool for the production of large quantities of the protein. This can be an important tool in kinetic studies as well as in production of antibodies for other analytical studies (immunoblot, immunohistochemical studies, etc.). Expression in the mammalian cells on the other hand, can provide a significant research tool to study the functional roles of stefin A in the mammalian systems such as the regulation of cysteine proteases.

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“…First, CTSL mRNA can be elevated in tumor cells either by enhanced transcription as observed in ErbB2 positive breast cancer (10) or by epigenetic regulation (11,12). Second, CTSL protein stability and activity may be modulated by protein turnover and expression of endogenous cathepsin inhibitors (13). Interestingly, regulation on the level of mRNA translation into protein has been brought up as another aspect of CTSL regulation.…”

mentioning

confidence: 99%

Stress-resistant Translation of Cathepsin L mRNA in Breast Cancer Progression

Tholen

Wolanski

Stolze

et al. 2015

Journal of Biological Chemistry

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Background: Translational regulation might underlie the high expression levels of the protease cathepsin L (CTSL) associated with poor breast cancer prognosis. Results: Translation of CTSL mRNA is highly stress-resistant and promotes metastasis of murine breast cancer. Conclusion: CTSL mRNA circumvents translational shutdown in cancer-associated stress conditions. Significance: High expression of a metastasis promoting protease is maintained by translational regulation.

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Expression of cysteine peptidase cathepsin L and its inhibitors stefins A and B in relation to tumorigenicity of breast cancer cell lines

Cited by 53 publications

References 10 publications

Cathepsin L Is Responsible for Processing and Activation of Proheparanase through Multiple Cleavages of a Linker Segment

Cathepsin L Is Responsible for Processing and Activation of Proheparanase through Multiple Cleavages of a Linker Segment

Functional expression of recombinant human stefin A in mammalian and bacterial cells

Stress-resistant Translation of Cathepsin L mRNA in Breast Cancer Progression

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