Mesenchymal neoplasms with NTRK and other kinase gene alterations

Kinase alterations are increasingly recognised as oncogenic drivers in mesenchymal tumours. Infantile fibrosarcoma and the related renal tumour, congenital mesoblastic nephroma, were among the first solid tumours shown to harbour recurrent tyrosine kinase fusions, with the canonical ETV6::NTRK3 fusion identified more than 20 years ago. Although targeted testing has long been used in diagnosis, the advent of more robust sequencing techniques has driven the discovery of kinase alterations in an array of mesenchymal tumours. As our ability to identify these genetic alterations has improved, as has our recognition and understanding of the tumours that harbour these alterations. Specifically, this study will focus upon mesenchymal tumours harbouring NTRK or other kinase alterations, including tumours with an infantile fibrosarcoma-like appearance, spindle cell tumours resembling lipofibromatosis or peripheral nerve sheath tumours and those occurring in adults with a fibrosarcoma-like appearance. As publications describing the histology of these tumours increase so, too, do the variety kinase alterations reported, now including NTRK1/2/3, RET, MET, RAF1, BRAF, ALK, EGFR and ABL1 fusions or alterations. To date, these tumours appear locally aggressive and rarely metastatic, without a clear link between traditional features used in histological grading (e.g. mitotic activity, necrosis) and outcome. However, most of these tumours are amenable to new targeted therapies, making their recognition of both diagnostic and therapeutic import. The goal of this study is to review the clinicopathological features of tumours with NTRK and other tyrosine kinase alterations, discuss the most common differential diagnoses and provide recommendations for molecular confirmation with associated treatment implications.     

Genomic variants within chromosome 14q32.32 regulate bone mass through MARK3 signaling in osteoblasts

Bone mineral density (BMD) is a highly heritable predictor of osteoporotic fracture. GWAS have identified hundreds of loci influencing BMD, but few have been functionally analyzed. In this study, we show that SNPs within a BMD locus on chromosome 14q32.32 alter splicing and expression of PAR-1a/microtubule affinity regulating kinase 3 (MARK3), a conserved serine/threonine kinase known to regulate bioenergetics, cell division, and polarity. Mice lacking Mark3 either globally or selectively in osteoblasts have increased bone mass at maturity. RNA profiling from Mark3-deficient osteoblasts suggested changes in the expression of components of the Notch signaling pathway. Mark3-deficient osteoblasts exhibited greater matrix mineralization compared with controls that was accompanied by reduced Jag1/Hes1 expression and diminished downstream JNK signaling. Overexpression of Jag1 in Mark3-deficient osteoblasts both in vitro and in vivo normalized mineralization capacity and bone mass, respectively. Together, these findings reveal a mechanism whereby genetically regulated alterations in Mark3 expression perturb cell signaling in osteoblasts to influence bone mass.     

10-MDP-钙盐形成对牙本质粘接成绩影响的评价

目的　分析10-MDP-钙盐形成对牙本质粘接成绩的影响。方法　采用酸蚀冲洗粘接模式，根据牙本质表面的处理方式和选择粘接剂的不同将牙齿随机分为以下4组（n=5）进行处理，制作牙本质/树脂粘接试件：①对照组，直接使用全酸蚀粘接剂Single bond 2(SB2)处理后粘接；②10-MDP组，使用SB2处理进行粘接前，牙本质表面以含有磷酸酯单体10-MDP的自配底涂剂预处理；③CHX组，使用SB2处理进行粘接前，先以氯己定（CHX）预处理牙本质表面;④SBU组，使用包含10-MDP的通用型粘接剂Single bond universal(SBU)处理后进行粘接。通过微拉伸测试（μTBS）测试粘接强度，以X射线衍射(XRD)、原位酶谱测试表征自配10-MDP底涂剂和两种牙本质粘接剂处理的牙本质表面，分析10-MDP-钙盐形成对牙本质粘接成绩的影响。结果　微拉伸结果显示，不同处理方式的粘接试件在24 h水储后没有表现出明显的统计学差异(P>0.1)；经过6个月的水储后，与10-MDP组和SBU组相比，对照组的微拉伸强度显著降低(P<0.05)，而CHX组的微拉伸强度没有明显变化(P>0.05)。XRD结果显示,在10-MDP组和SBU组均检测到10-MDP-钙盐形成的特征性峰，表明有10-MDP-钙盐的形成。原位酶谱结果显示，10-MDP组与SBU组之间混合层荧光强度没有明显区别，但均明显高于对照组，CHX组荧光强度低于10-MDP组与SBU组。结论　10-MDP-钙盐的形成能够保护暴露的胶原纤维不接触到MMPs而免于水解，从而增强牙本质/树脂的粘接成绩。