Crosstalk between apoptosis and antioxidants in melanoma vasculogenic mimicry

ROS Pleiotropy in Melanoma and Local Therapy with Physical Modalities

Metabolic energy production naturally generates unwanted products such as reactive oxygen species (ROS), causing oxidative damage. Oxidative damage has been linked to several pathologies, including diabetes, premature aging, neurodegenerative diseases, and cancer. ROS were therefore originally anticipated as an imperative evil, a product of an imperfect system. More recently, however, the role of ROS in signaling and tumor treatment is increasingly acknowledged. This review addresses the main types, sources, and pathways of ROS in melanoma by linking their pleiotropic roles in antioxidant and oxidant regulation, hypoxia, metabolism, and cell death. In addition, the implications of ROS in various physical therapy modalities targeting melanoma, such as radiotherapy, electrochemotherapy, hyperthermia, photodynamic therapy, and medical gas plasma, are also discussed. By including ROS in the main picture of melanoma skin cancer and as an integral part of cancer therapies, a greater understanding of melanoma cell biology is presented, which ultimately may elucidate additional clues on targeting therapy resistance of this most deadly form of skin cancer.

The role of vascular mimicry as a biomarker in malignant melanoma: a systematic review and meta-analysis

BACKGROUND

Vasculogenic mimicry (VM) a microvascular system consisting of non-endothelial cells that is newly formed by aggressive tumors, has been proposed as an important therapeutic target in malignant melanoma (MM). We performed a systematic literature review to evaluate the diagnostic and prognostic accuracy of VM status for overall survival of MM patients.

METHODS

The quality of the included studies was evaluated using the QUADAS-2 tool. Diagnostic capacity of VM variables, including sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and the area under summary receiver operating characteristic (SROC), were pooled using Meta-DiSc software.

RESULTS

A retrospective observational study was conducted based on twelve clinical studies including 978 clinically confirmed melanoma patients with proportion (P). VM+ melanoma cells were associated with poor prognosis in 38% of MM group (P = 0.35, 95% confidence intervals (CI): 0.27-0.42, p < 0.001). The pooled sensitivity and specificity were 0.82 (95% CI: 0.79-0.84) and 0.69 (95% CI: 0.66-0.71), respectively. Furthermore, the pooled PLR, NLR, and DOR were 2.56 (95% CI: 1.94-3.93), 0.17 (95% CI: 0.07-0.42), and 17.75 (95% CI: 5.30-59.44), respectively. Furthermore, the AUC of SROC was 0.63, indicating high reliability of VM status as a biomarker. Importantly, subgroup results suggested that VM+ status is a significantly accurate prognostic biomarker when diagnosed by the CD31-/PAS+ staining methods in Asian MM samples (p < 0.001).

CONCLUSIONS

Our findings support the potential of VM status of tumors as a promising prognostic biomarker and emphasize an effective adjuvant therapeutic strategy in the prognosis of Asian MM patients.

Vasculogenic mimicry: Possible role of effector caspase-3, caspase-6 and caspase-7

Vasculogenic mimicry (VM) describes the process by which aggressive cancer cells form extracellular matrix-rich, vessel-like mesh works, which supply nutrients and oxygen. Furthermore, it offers a new route for tumor cell invasion and metastasis and thus a correspondingly poor prognosis and survival rate for affected patients. Effector caspases are well known for their apoptotic function, whereas a non-apoptotic function in tumor progression is highly disputed. Caspase-3, -6 and -7 are expressed in aggressive tumor cells in a non-mutated form, indicating an active function independent of apoptosis. This review summarizes the possible functions of the above-mentioned caspases in VM. We also discuss the possible involvement of caspases in potential mechanisms towards the formation of vessel-like structures. Furthermore, this review illustrates the importance of new studies in the ongoing investigation into the role of effector caspases in VM, invasion, and migration of aggressive tumor cells.

[Expression of CD82/KAI1 and HIF-1α in non-small cell lung cancer and their relationship to vasculogenic mimicry]

背景与目的

新近研究显示血管生成拟态存在于多种高侵袭性肿瘤中, 并与肿瘤细胞的侵袭、转移特性有关, 在形成血管生成拟态的肿瘤中有多种基因表达异常。本研究旨在寻找能预测非小细胞肺癌(non-small cell lung cancer, NSCLC)浸润、转移及术后生存率的指标。

方法

采用免疫组化Elivision^TM plus法和特殊组织化学法检测160例NSCLC和20例正常肺组织中缺氧诱导因子-1α(hypoxia inducible factor-1α, HIF-1α)、CD82/KAI1的表达和血管生成拟态(vasculogenic mimicry, VM)情况。

结果

在正常肺组织中HIF-1α、CD82/KAI1的表达率和VM分别为0、95.0%和0, 在NSCLC组织中分别为48.8%、37.5%和36.9%, 差异有统计学意义(P < 0.01);其水平与肿瘤细胞分化程度、淋巴结转移、临床分期和术后生存期有关(P < 0.01);CD82/KAI1的表达与HIF-1α的表达以及VM呈负相关, HIF-1α的表达水平与VM呈正相关(P < 0.05);CD82/KAI1、HIF-1α的表达以及VM均与微血管密度(microvessel density, MVD)有关联性(P < 0.01)。Kaplan-Meier生存分析表明HIF-1α的过表达和VM均与患者的生存率有关, 阳性的患者生存率明显低于阴性者(P < 0.01);而CD82/KAI1阳性表达的患者生存率明显高于阴性者(P < 0.01);MVD≥22的5年生存率明显低于MVD < 22的生存率(P < 0.01)。多因素分析:pTNM分期、CD82/KAI1、HIF-1α的表达以及VM是影响NSCLC根治术后患者预后的独立因素(P < 0.01)。

结论

CD82/KAI1、HIF-1α在NSCLC组织中的表达水平以及VM与肿瘤的分化程度、转移和预后等均有关, CD82/KAI1、HIF-1α和VM联合检测对NSCLC的进展及预后判断有重要意义。

Molecular regulation of vasculogenic mimicry in tumors and potential tumor-target therapy

“Vasculogenic mimicry (VM)”, is a term that describes the unique ability of highly aggressive tumor cells to express a multipotent, stem cell-like phenotype, and form a pattern of vasculogenic-like networks in three-dimensional culture. As an angiogenesis-independent pathway, VM and/or periodic acid-schiff-positive patterns are associated with poor prognosis in tumor patients. Moreover, VM is resistant to angiogenesis inhibitors. Here, we will review the advances in research on biochemical and molecular signaling pathways of VM in tumors and on potential anti-VM therapy strategy.