Cancer Stem Cells and Circulatory Tumor Cells Promote Breast Cancer Metastasis

Breast cancer (BC) is a highly metastatic, pathological cancer that significantly affects women worldwide. The mortality rate of BC is related to its heterogeneity, aggressive phenotype, and metastasis. Recent studies have highlighted that the tumor microenvironment (TME) is critical for the interplay between metastasis mediators in BC. BC stem cells, tumor-derived exosomes, circulatory tumor cells (CTCs), and signaling pathways dynamically remodel the TME and promote metastasis. This review examines the cellular and molecular mechanisms governing the epithelial to mesenchymal transition (EMT) that facilitate metastasis. This review also discusses the role of cancer stem cells (CSCs), tumor-derived exosomes, and CTs in promoting BC metastasis. Furthermore, the review emphasizes major signaling pathways that mediate metastasis in BC. Finally, the interplay among CSCs, exosomes, and CTCs in mediating metastasis have been highlighted. Therefore, understanding the molecular cues that mediate the association of CSCs, exosomes, and CTCs in TME helps to optimize systemic therapy to target metastatic BC.     

Molecular mediators of breast cancer metastasis

Breast cancer has the highest incidence rate of malignancy in women worldwide. A major clinical challenge faced by patients with breast cancer treated by conventional therapies is frequent relapse. This relapse has been attributed to the cancer stem cell (CSC) population that resides within the tumor and possess stemness properties. Breast CSCs are generated when breast cancer cells undergo epithelial-mesenchymal transition resulting in aggressive, highly metastatic, and invasive phenotypes that exhibit resistance towards chemotherapeutics. Metastasis, a phenomenon that aids in the migration of breast CSCs, occurs through any of three different routes: hematogenous, lymphatic, and transcoelomic. Hematogenous dissemination of breast CSCs leads to metastasis towards distant unrelated organs like lungs, liver, bone, and brain causing secondary tumor generation. Activation of metastasis genes or silencing of metastasis suppressor genes often leads to the advancement of metastasis. This review focuses on various genes and molecular factors that have been implicated to regulate organ-specific breast cancer metastasis by defying the available therapeutic interventions.     

Metastasis of oral squamous cell carcinoma to the parotid lymph nodes

Parotid lymph node (PLN) metastasis greatly worsens the prognosis of patients with oral squamous cell carcinoma (OSCC) and poses a great challenge for further treatment of OSCC. The clinicopathological characteristics and treatment strategies for PLN metastasis from OSCC need to be comprehensively elucidated. A retrospective review of OSCC patients who experienced postoperative PLN metastasis in our department between 2000 and 2018 was performed in this study. A total of 47 OSCC patients with postoperative PLN metastasis were identified. PLN with metastasis were divided into three groups based on the location: parotid tail (PLN-t), superficial lobe (PLN-sl), and deep lobe (PLN-dl). Most of the patients experienced PLN metastasis within less than 12 months after the primary surgery for OSCC. Comparatively, patients with PLN-sl metastasis were more prone to have infiltration of the facial nerve. The tongue and buccal mucosa were the most frequent primary sites associated with PLN metastasis from OSCC. PLNs in the parotid tail were most commonly affected by the metastasized OSCC. Consequently, we recommend a series of strategies for the prevention and treatment of PLN metastasis for OSCC patients. In conclusion, PLNs should not be overlooked during preoperative evaluation and postoperative follow-up examinations for OSCC patients.     

腹腔镜联合髂腹股沟淋巴结清扫术在黑色素瘤淋巴结转移中的应用

目的探讨腹腔镜联合髂腹股沟淋巴结清扫术在黑色素瘤淋巴结转移中的应用效果。 方法回顾性分析第四军医大学西京医院2015年5月至2017年2月收治的9例转移性黑色素瘤患者，均为下肢原发灶切除术后、IFN-β治疗期间经影像学检查发现髂血管旁和(或)腹股沟区淋巴结转移。手术方式为腹腔镜自髂血管分叉逆行清扫髂血管旁淋巴结，开放手术清扫腹股沟区淋巴结。 结果9例手术均顺利完成。平均手术时间(150.9±41.08)min、平均术中出血量(55±21.51)ml、平均术后下床活动时间(3.11±1.67)d、平均术后住院时间(8.57±2.19)d，术后病理均证实为髂血管旁淋巴结和(或)腹股沟区淋巴结转移。 结论腹腔镜联合髂腹股沟淋巴结清扫术是治疗下肢黑色素瘤转移的新术式探索，该术式手术创伤较小、恢复较快、清扫彻底，具备一定的临床应用价值。     

肿瘤相关巨噬细胞促进宫颈癌侵袭转移的机制研究

 目的 研究肿瘤相关巨噬细胞（tumor-associated macrophages, TAMs）对宫颈癌侵袭转移的影响及分子机制。方法 免疫组织化学法检测宫颈病变组织TAMs的浸润情况。对人单核巨噬细胞系THP1进行体外诱导分化，使其转化为M2型TAMs。取TAMs上清液刺激宫颈癌细胞SiHa和C33a。划痕法、Transwell法分别检测TAMs对宫颈癌细胞系迁移和侵袭能力的影响。Western blot检测刺激后宫颈癌细胞上皮间质转化进程及MMP-9的表达。结果 TAMs浸润数目与宫颈病变进展呈正相关。TAMs上清液刺激后，SiHa和C33a细胞出现间质样改变，而且迁移和侵袭能力显著增强（均P<0.5）。TAMs可下调E-Cadherin的表达，上调N-Cadherin、Vimentin及MMP-9的表达。结论 TAMs浸润与宫颈上皮恶性转化和进展密切相关，TAMs可能通过上调MMP-9的表达促进宫颈癌细胞侵袭转移。