MCT4 and CD147 colocalize with MMP14 in invadopodia and support matrix degradation and invasion by breast cancer cells

Research progress on the regulatory role of lactate and lactylation in tumor microenvironment

The tumor microenvironment (TME) arises from the dynamic interactions between tumor cells and the surrounding medium, including a variety of cell types and extracellular components, which have an important impact on the genesis and development of tumors. A key player in TME is lactate, a metabolic byproduct of glycolysis, which serves as a significant energy source. Lactate has direct implications on the survival and differentiation of immune cells, the metabolic reprogramming and progression of tumor cells. Moreover, lactylation, a unique post-translational modification, exerts a regulatory effect on TME by affecting gene transcription via adding lactate groups to both histone and non-histone proteins. This review systematically and comprehensively synthesizes emerging evidence on how the lactate-lactylation axis drives immune evasion, therapy resistance, and TME remodeling, highlighting the therapeutic targets related to lactate and lactylation that dismantle this metabolic-epigenetic crosstalk.

Decoding the MMP14 integrin link: Key player in the secretome landscape

Rapid progress has been made in the exciting field of secretome research in health and disease. The tumor secretome, which is a significant proportion of the tumor proteome, is secreted into the extracellular space to promote intercellular communication and thus tumor progression. Among the many molecules of the secretome, integrins and matrix metalloproteinase 14 (MMP14) stand out as the interplay of adhesion and proteolysis drives invasion. Integrins serve as mechanosensors that mediate the contact of cells with the scaffold of the extracellular matrix and are significantly involved in the precise positioning and activity control of the membrane-bound collagenase MMP14. As a secretome proteinase, MMP14 influences and modifies the secretome itself. While integrins and MT-MMPs are membrane bound, but can be released and are therefore border crossers between the cell surface and the secretome, the extracellular matrix is not constitutively cell-bound, but its binding to integrins and other cell receptors is a stringently regulated process. To understand the mutual interactions in detail, we first summarize the structure and function of MMP14 and how it is regulated at the enzymatic and cellular level. In particular, the mutual interactions between integrins and MMP14 include the proteolytic cleavage of integrins themselves by MMP14. We then review the biochemical, cell biological and physiological effects of MMP14 on the composition and associated functions in the tumor secretome when either bound to the cell membrane, or located on extracellular microvesicles, or as a proteolytically shed non-membrane-bound ectodomain. Novel methods of proteomics, including the analysis of extravesicular vesicles, and new methods for the quantification of MMP14 will provide new research and diagnostic tools. The proteolytic modification of the tumor secretome, especially by MMP14, may bring an additional aspect to tumor secretome studies and will have an impact on the diagnosis and most likely also on the therapy of cancer patients.

Pain, lactate, and anesthetics: intertwined regulators of tumor metabolism and immunity

Patients with advanced cancer frequently endure severe pain, which substantially diminishes their quality of life and can adversely impact survival. Analgesia, a critical modality for alleviating such pain, is now under scrutiny for its potential role in cancer progression, a relationship whose underlying mechanisms remain obscure. Emerging evidence suggests that lactate, once considered a metabolic byproduct, actively participates in the malignant progression of cancer by modulating both metabolic and immunological pathways within the tumor microenvironment. Furthermore, lactate is implicated in the modulation of cancer-related pain, exerting effects through direct and indirect mechanisms. This review synthesizes current understanding of lactate's production, transport, and functional roles in tumor cells, encompassing the regulation of tumor metabolism, immunity, and progression. Additionally, we dissect the complex, bidirectional relationship between lactate and pain, and assess the impact of anesthetics on pain relief, lactate homeostasis, and tumorigenesis.