Vasculogenic mimicry:a pivotal mechanism contributing to drug resistance in antiangiogenic therapy

The growth of solid tumors relies on establishing a robust blood supply,with angiogenesis playing a key role in this intricate process.Based on this understanding,therapeutic strategies targeting tumor angiogenesis have been developed.However,the clinical effectiveness of antiangiogenic therapy(AAT)in treating tumors has not lived up to expectations.In recent years,vasculogenic mimicry(VM)has attracted increasing attention from the academic community as a longstanding but often overlooked mechanism of nonangiogenic tumor vascularization.Within the tumor microenvironment,neoplastic cells can autonomously form vessel-like structures,creating a blood supply that does not rely on endothelial cells.This phenomenon,known as VM,is a critical marker of aggressive tumors and may play a significant role in conferring resistance to AAT.In this review,we thoroughly examine the evidence,clinical characteristics,and mechanisms of VM across various tumor types and explore its potential role and importance in resistance to AAT and the development of new antitumor therapies.

Antiangiogenic therapy with bevacizumab in recurrent malignant gliomas： analysis of the response and core pathway aberrations

Background Bevacizumab, a humanized monoclonal antibody against vascular endothelial growth factor, has shown promising activity in recurrent malignant gliomas. We reported the treatment response for the combination of bevacizumab and chemotherapy in a series of six patients with recurrent malignant glioma and investigated the molecular alterations in cancer pathways using the surgical biopsies from these patients. Methods Standard therapy with primary resection followed by adjuvant chemoradiotherapy had failed in all patients. Bevacizumab was administered at a dose of 10 mg/kg every 2 weeks. Concomitantly, four patients received temozolomide （50 mg·m^-2·d^-1）, one patient irinotecan （125 mg/m^2 every 2 weeks） and one patient topotecan （1.2 mg·m^-2·d^-1）. Response to therapy was mainly determined by magnetic resonance imaging. The expression of Ras, phosphorylated mitogen activated protein kinase （p-MAPK）, phosphorylated AKT （p-AKT）, phosphorylated mammalian target of rapamycin （p-mTOR） and phosphorylated signal transducer and activator of transcription 3 （p-STAT3） were semiquantitatively assessed by immunohistochemistry using surgical biopsies before the initial treatment. Results Five of the six patients had a radiographic response. Three were complete response, and two were partial response. Only one patient had progressive disease. The 6-month progession-free survival （PFS） was 33% and the median PFS was 15 weeks, with a range of 6 to more than 60 weeks. Of the three core pathways analyzed in this study, the Ras/MAPK and phosphatidylinositol-3-kinase （PI3K）/AKT/mTOR pathways were more likely to be associated with the treatment response to bevacizumab. In two younger patients （ages 〈50） with complete response, simultaneous overexpression of p-MAPK, p-AKT and p-mTOR might be the crucial feature. Conclusions Bevacizumab in combination with chemotherapeutic agents may be an effective strategy for patients with recurrent malignant glioma. Activated MAPK and AKT might be possible biomarkers for selecting suitable patients for this targeted therapy.

Immunotherapy for mucosal melanoma

Mucosal melanoma(MM)is extremely rare in Caucasians,whereas it is the second predominant melanoma subtype in Asian and other non-Caucasian populations.Distinct from cutaneous melanoma in terms of epidemiology,biology,and molecular characteristics,MM is characterized by more aggressive biological behavior,lower mutational burden,more chromosomal structure variants,and poorer prognosis.Because of the rarity of MM,its biological features are not fully understood,and potential novel therapies are less well depicted.Whereas immunotherapy has shown encouraging efficacy for cutaneous melanoma,its efficacy in MM is unclear due to limited sample sizes in clinical trials.Thus,in this review,we describe the epidemiological,clinical,and molecular features of MM and summarize the efficacies of different immunotherapies for MM,including immune checkpoint inhibitors,vaccines,oncolytic virus therapy,adoptive T-cell therapy,and various combination therapies.

Three novel rare TP53 fusion mutations in a patient with multiple primary cancers:a case report

As survival rates improve and detection technologies advance,the occurrence of multiple primary cancers(MPCs)has been increasing.Approximately 16%of cancer survivors develop a subsequent malignancy,with lung cancer often developing after esophageal cancer due to potential“field cancerization”effects.Despite this observation,the genetic heterogeneity underlying MPCs remains understudied.However,the recent emergence of genetic testing has expanded the scope of investigations into MPCs to investigate signatures underlying cancer predisposition.This report reveals 3 unprecedented TP53 fusion mutations in a Chinese patient afflicted by MPCs,namely,AP1M2–TP53(A1;T11)fusion,TP53–ILF3(T10;I13)fusion,and SLC44A2–TP53(S5;T11)fusion.This patient exhibited an extended period of survival after diagnosis of extensive-stage small cell lung cancer,which occurred 6 years after the diagnosis of esophageal squamous cell cancer.This unique reportmay provide supplementary data that enhance our understanding of the genetic landscape ofMPCs.

Metastatic thymic-enteric adenocarcinoma responding to chemoradiation plus anti-angiogenic therapy:A case report

BACKGROUND Thymic-enteric adenocarcinoma with positive expression of CDX2 and CK20 is rare in adults,with only 16 reported cases.However,standard treatment options for this type of thymic adenocarcinoma has not yet been established.Therefore,we report a case of stage IV thymic-enteric adenocarcinoma treated with radiotherapy,chemotherapy,and anti-angiogenesis therapy.CASE SUMMARY We report a case of thymic-enteric adenocarcinoma occurring in a 44-year-old woman.The tumor was considered unresectable owing to its invasiveness.The patient was treated with six cycles of oxaliplatin(130 mg/m^(2),day 1)and capecitabine(1000 mg/m^(2) BID,days 1-14).During the first three cycles of chemotherapy,concurrent radiotherapy(60 Gy/30 fractions)and anti-angiogenic therapy using apatinib were recommended.The primary tumor achieved partial remission based on the Response Evaluation Criteria in Solid Tumors.During follow-up,there was no evidence of disease relapse,except a high serum CA19-9 level.The patient is alive and regularly followed.Based on the previous literature and the present case,we believe that early diagnosis of thymic-enteric adenocarcinoma is important.CONCLUSION XELOX(capecitabine plus oxaliplatin)combined with radiotherapy is an optional therapy for inoperable thymic-enteric adenocarcinoma.

Regulation and function of angiogenic factors in chronic lymphocytic leukemia

Progression of chronic lymphocytic leukemia(CLL)is determined by the localization of malignant cells in lymphoid tissues,where they receive growth and survival signals.CLL cells produce angiogenic factors that are regulated by internal and external stimuli and whose levels vary according to the clinical stage of the disease.Stromal cellular and molecular components in CLL niches disturb the balance of pro-and antiangiogenic molecules in CLL cells and induce an angiogenic switch.Additionally,CLL cells also influence the behavior of microenvironmental cells,inducing endothelial cell proliferation and increasing the angiogenic capacity of macrophages,neutrophils,and other cells present in CLL niches.As a result of these reciprocal functional interactions,bone marrow angiogenesis is frequently increased in CLL and has been proposed as a prognostic marker in early disease.Besides their role in regulating angiogenesis,angiogenic factors are also involved in CLL cell migration and survival,all contributing to disease progression.Angiogenic factors,particularly vascular endothelial growth factor,have therefore been attractive therapeutic targets in CLL and many clinical trials were established in the past years.However,the results of these trials reveal that anti-angiogenic therapies alone are not as efficient as expected and should rather be used in combination with other treatments.