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Development of palliative medicine in the United Kingdom and Ireland
Published in Eduardo Bruera, Irene Higginson, Charles F von Gunten, Tatsuya Morita, Textbook of Palliative Medicine and Supportive Care, 2015
The chemotherapy drugs that cause CIPN are too large to penetrate an intact blood-brain barrier. A variant of this barrier in the PNS, the blood-nerve barrier, is permeable to these molecules, which accumulate and bind to axons and dorsal root ganglion (DRG) cells (Figure 119.1). The result is damage of microtubules, interference with axonal transport, and mitochondrial death. Current research points to a contributory role of cytokines (IL-6 and IL-8) and the matrix metalloproteinases MMP2, MMP3, and MMP24 in the pathogenesis of peripheral nerve injury by chemotherapy [2]. There is also evidence from animal models of paclitaxel-induced neuropathy that the reactive oxygen species superoxide radical O2-and hydroxyl radical OH-, by-products of the mitochondrial oxidative phosphorylation, are key mediators in neuropathic pain [3]. Although myelin can be a target of chemotherapy drugs, it seems this is more a consequence of the axonal damage than a direct attack on Schwann cells [4].
Comprehensive analysis of matrix metalloproteinases and their inhibitors in head and neck squamous cell carcinoma
Published in Acta Oncologica, 2022
Mingyuan Zou, Chen Zhang, Yan Sun, Huina Wu, Feng Xiao, Wei Gao, Fengfeng Zhao, Xiaobo Fan, Guoqiu Wu
MMPs are a family member of calcium- and zinc-dependent endopeptidases involved in extracellular matrix (ECM) proteins, including collagen, fibronectin, laminin, elastin, and proteoglycans [11,12]. Because of their ability to degrade the ECM, MMPs are elevated in several human patient tumor samples, including ovarian cancer [13,14], prostate cancer [15], and breast cancer [16], and MMP levels are positively correlated with cancer progression. To date, 24 members of the MMP family have been identified in humans, as summarized in Figure S1. Of note, the terms MMP4, MMP5, MMP6, MMP18, and MMP22 are not used in humans because they correspond to MMP17, MMP24, MMP25, MMP19, and MMP27, respectively. In addition, there are two equivalent forms of MMP23 (MMP23A and MMP23B) in humans that are encoded by two distinct genes, and MMP23A is a pseudogene [17]. According to their structure and substrate specificities, MMP gene family can be classified into subgroups of collagenases (−1, −8 and −13), stromelysins (−3, −10 and −11), gelatinases (−2 and −9), matrilysins (−7 and −26), membrane-type (-14, −15, −16, −17, −23, −24 and −25), and other MMPs (−12, −19, −20, −21, −27 and −28) [18,19]. Further, a corresponding family named tissue inhibitors of metalloproteinases (TIMPs), which include four members (TIMP1 to TIMP4), are natural inhibitors of MMPs [20,21]. ECM integrity and remodeling depend on the dynamic balance between remodeling enzymes (MMPs) and their inhibitors (TIMPs) [22,23]. Likewise, studies on the expression of TIMPs in HNSCC and their roles in prognosis are limited, and their results are controversial.