Clinical trials in cancer screening, prevention and early diagnosis (SPED): a systematic mapping review.

BACKGROUND: Global annual cancer incidence is forecast to rise to 27.5 M by 2040, a 62% increase from 2018. For most cancers, prevention and early detection are the most effective ways of reducing mortality. This study maps trials in cancer screening, prevention, and early diagnosis (SPED) to identify areas of unmet need and highlight research priorities. METHODS: A systematic mapping review was conducted to evaluate all clinical trials focused on cancer SPED, irrespective of tumour type. The National Cancer Research Institute (NCRI) portfolio, EMBASE, PubMed and Medline were searched for relevant papers published between 01/01/2007 and 01/04/2020. References were exported into Covidence software and double-screened. Data were extracted and mapped according to tumour site, geographical location, and intervention type. RESULTS: One hundred seventeen thousand seven hundred one abstracts were screened, 5157 full texts reviewed, and 2888 studies included. 1184 (52%) trials focussed on screening, 554 (24%) prevention, 442 (20%) early diagnosis, and 85 (4%) a combination. Colorectal, breast, and cervical cancer comprised 61% of all studies compared with 6.4% in lung and 1.8% in liver cancer. The latter two are responsible for 26.3% of global cancer deaths compared with 19.3% for the former three. Number of studies varied markedly according to geographical location; 88% were based in North America, Europe, or Asia. CONCLUSIONS: This study shows clear disparities in the volume of research conducted across different tumour types and according to geographical location. These findings will help drive future research effort so that resources can be directed towards major challenges in cancer SPED.

Membrane-type 1 matrix metalloproteinase as predictor of survival and candidate therapeutic target in Ewing sarcoma.

BACKGROUND: Ewing sarcoma (ES) is the second most common primary bone malignancy, with an urgent need for new treatments. ES is associated with high rates of progression and relapse, driven by drug-resistant cells capable of migration, self-renewal and single-cell tumorigenesis, termed cancer stem-like cells (CSCs). Membrane-type 1 matrix metalloproteinase (MT1-MMP) is a membrane-bound proteolytic enzyme, which, via direct and indirect mechanisms, digests four of the main types of collagen. This can be hijacked in malignancy for invasion and metastasis, with high expression predicting decreased survival in multiple cancers. In this study, we have examined the hypothesis that MT1-MMP is expressed by ES cells and explored the relationship between expression and outcomes. PROCEDURE: MT1-MMP expression in ES established cell lines, primary patient-derived cultures and daughter ES-CSCs was characterised by RNA sequencing, Western blotting, immunocytochemistry and flow cytometry. Immunohistochemistry was used to detect MT1-MMP in tumour biopsies, and the relationship between expression, event-free and overall survival examined. RESULTS: MT1-MMP was detected at both RNA and protein levels in five of six established cell lines, all primary cultures (n = 25) and all daughter ES-CSCs (n = 7). Immunohistochemistry of treatment-naïve biopsy tissue demonstrated that high MT1-MMP expression predicted decreased event-free and overall survival (p = .017 and .036, respectively; n = 47); this was not significant in multivariate analysis. CONCLUSIONS: MT1-MMP is expressed by ES cells, including ES-CSCs, making it a candidate therapeutic target. The level of MT1-MMP expression at diagnosis may be considered as a prognostic biomarker if validated by retrospective analysis of a larger cohort of clinical trial samples.

CCI52 sensitizes tumors to 6-mercaptopurine and inhibits MYCN-amplified tumor growth.

The antimetabolite 6-mercaptopurine (6-MP) is an important component in the treatment of specific cancer subtypes, however, the development of drug resistance and dose-limiting toxicities can limit its effectiveness. The therapeutic activity of 6-MP requires cellular uptake, enzymatic conversion to thio-GMP and incorporation of thio-GTP into RNA and DNA, as well as inhibition of de novo purine synthesis by methyl-thio-IMP. Mechanisms that prevent 6-MP entry into the cell, prevent 6-MP metabolism or deplete thiopurine intermediates, can all lead to 6-MP resistance. We previously conducted a high-throughput screen for inhibitors of the multidrug transporter MRP4 using 6-MP sensitivity as the readout. In addition to MRP4-specific inhibitors, we identified a compound, CCI52, that sensitized cell lines to 6-MP independent of this transporter. CCI52 and its more stable analogue CCI52-14 also function as effective chemosensitizers in vivo, substantially extending survival in a transgenic mouse cancer model treated with 6-MP. Chemosensitization was associated with an increase in thio-IMP, suggesting that CCI52 functions directly on 6-MP uptake or metabolism. In addition to its chemosensitizing effects, CCI52 and CCI52-14 inhibited the growth of MYCN-amplified high-risk neuroblastoma cell lines and delayed tumor progression in a MYCN-driven, transgenic mouse model of neuroblastoma. These multifunctional inhibitors may be useful for the further development of anticancer agents and as tools to better understand 6-MP metabolism.

Chemotherapy induces Notch1-dependent MRP1 up-regulation, inhibition of which sensitizes breast cancer cells to chemotherapy.

BACKGROUND: Multi-drug Resistance associated Protein-1 (MRP1) can export chemotherapeutics from cancer cells and is implicated in chemoresistance, particularly as is it known to be up-regulated by chemotherapeutics. Our aims in this study were to determine whether activation of Notch signalling is responsible for chemotherapy-induced MRP1 expression Notch in breast cancers, and whether this pathway can be manipulated with an inhibitor of Notch activity. METHODS: MRP1 and Notch1 were investigated in 29 patients treated with neoadjuvant chemotherapy (NAC) for breast cancer, using immunohistochemistry on matched biopsy (pre-NAC) and surgical samples (post-NAC). Breast epithelial cell cultures (T47D, HB2) were treated with doxorubicin in the presence and absence of functional Notch1, and qPCR, siRNA, Western blots, ELISAs and flow-cytometry were used to establish interactions. RESULTS: In clinical samples, Notch1 was activated by neoadjuvant chemotherapy (Wilcoxon signed-rank p < 0.0001) and this correlated with induction of MRP1 expression (rho = 0.6 p = 0.0008). In breast cell lines, doxorubicin induced MRP1 expression and function (non-linear regression p < 0.004). In the breast cancer line T47D, doxorubicin activated Notch1 and, critically, inhibition of Notch1 activation with the γ-secretase inhibitor DAPT abolished the doxorubicin-induced increase in MRP1 expression and function (t-test p < 0.05), resulting in enhanced cellular retention of doxorubicin and increased doxorubicin-induced apoptosis (t-test p = 0.0002). In HB2 cells, an immortal but non-cancer derived breast cell line, Notch1-independent MRP1 induction was noted and DAPT did not enhance doxorubicin-induced apoptosis. CONCLUSIONS: Notch inhibitors may have potential in sensitizing breast cancer cells to chemotherapeutics and therefore in tackling chemoresistance.