SPARC family proteins: matricellular modulators of cancer progression and therapeutic resistance

Area of Science:

• Biochemistry
• Molecular Biology
• Oncology

Background:

• The SPARC (secreted protein acidic and rich in cysteine) family comprises matricellular proteins regulating extracellular matrix (ECM) dynamics and tissue homeostasis.
• These proteins, including SPARC, SPARCL1, SPOCK1-3, SMOC1-2, and FSTL1, are frequently dysregulated in cancer via epigenetic changes, microRNAs, and tumor microenvironment (TME) interactions.

Purpose of the Study:

• To synthesize current knowledge on SPARC family structure, regulation, and context-specific functions in cancer-TME interactions.
• To highlight their dual roles in modulating tumor progression and resistance.
• To underscore their emerging utility in precision oncology and the need for biomarker development and targeted therapies.

Main Methods:

• Literature review and synthesis of existing research on SPARC family proteins in cancer.
• Analysis of their roles in ECM remodeling, epithelial-mesenchymal transition (EMT), cancer stemness, immune modulation, and drug resistance.
• Integration of mechanistic insights with translational advances.

Main Results:

• Dysregulation of SPARC family members, particularly SPARC, SPARCL1, SPOCK1, and SPOCK2, is pronounced in aggressive malignancies.
• These proteins drive tumor progression through various mechanisms, with context-dependent tumor-suppressive or oncogenic effects.
• Despite challenges in direct targeting, indirect strategies show preclinical promise, and their secreted nature suggests potential as biomarkers.

Conclusions:

• SPARC family proteins play complex, context-dependent roles in cancer, influencing progression and resistance.
• Their dysregulation in aggressive cancers highlights their significance.
• Further understanding is crucial for developing effective biomarkers and targeted therapeutic strategies in precision oncology.