Immunophenotyping of Orthotopic Homograft (Syngeneic) of Murine Primary KPC Pancreatic Ductal Adenocarcinoma by Flow Cytometry

Homograft (syngeneic) tumors are the workhorse of today&#39;s immuno-oncology (I/O) preclinical research. The tumor microenvironment (TME), particularly ...

Crown Bioscience Inc.

Peking University

A new series of 2,4-diamino pyrimidine derivatives with a sulfone-substituted pyrazole right side-chain were discovered as potent anaplastic lymphoma kinase inhibitors. Structure-activity relationship of the left side-chain on phenyl substitutions were explored which delivered many potent ALK inhibitors. Among them, 29a showed favorable pharmacokinetic profiles in rats and dogs together with significant antitumor efficacy in EML4-ALK fusion xenograft model.

Discovery of 2-arylamino-4-(1-methyl-3-isopropylsulfonyl-4-pyrazol-amino)pyrimidines as potent anaplastic lymphoma kinase (ALK) inhibitors.

Anaplastic lymphoma kinase (ALK) is a highly attractive therapeutic target for the treatment of some non-small cell lung cancer patients. This Letter describes the further SAR exploration on the novel 3-sulfonylpyrazol-4-amino pyrimidine scaffold. This work identified a compound 53 with very good in vitro/in vivo efficacies, good DMPK properties together with better hERG tolerability and it is currently being profiled for the evaluation as a potential pre-clinical candidate. 

Design and synthesis of novel 3-sulfonylpyrazol-4-amino pyrimidines as potent anaplastic lymphoma kinase (ALK) inhibitors.

The Cancer Genome Atlas (TCGA) project has generated abundant genomic data for human cancers of various histopathology types and enabled exploring cancer molecular pathology per big data approach. We developed a new algorithm based on most differentially expressed genes (DEG) per pairwise comparisons to calculate correlation coefficients to be used to quantify similarity within and between cancer types. We systematically compared TCGA cancers, demonstrating high correlation within types and low correlation between types, thus establishing molecular specificity of cancer types and an alternative diagnostic method largely equivalent to histopathology. Different coefficients for different cancers in study may reveal that the degree of the within-type homogeneity varies by cancer types. We also performed the same calculation using the TCGA-derived DEGs on patient-derived xenografts (PDX) of different histopathology types corresponding to the TCGA types, as well as on cancer cell lines. We, for the first time, demonstrated highly similar patterns for within- and between-type correlation between PDXs and patient samples in a systematic study, confirming the high relevance of PDXs as surrogate experimental models for human diseases. In contrast, cancer cell lines have drastically reduced expression similarity to both PDXs and patient samples. The studies also revealed high similarity between some types, for example, LUSC and HNSCC, but low similarity between certain subtypes, for example, LUAD and LUSC. Our newly developed algorithm seems to be a practical diagnostic method to classify and reclassify a disease, either human or xenograft, with better accuracy than traditional histopathology. Cancer Res; 76(16); 4619-26. ©2016 AACR.

Molecular Pathology of Patient Tumors, Patient-Derived Xenografts, and Cancer Cell Lines.

Although proteasome inhibitors such as bortezomib had significant therapeutic effects in multiple myeloma and mantel cell lymphoma, they exhibited minimal clinical activity as a monotherapy for solid tumors, including colorectal cancer. We found in this study that proteasome inhibition induced a remarkable nuclear exportation of ubiquitinated proteins. Inhibition of CRM1, the nuclear export carrier protein, hampered protein export and synergistically enhanced the cytotoxic action of bortezomib on colon cancer cells containing wild-type p53, which underwent G-M cell-cycle block and apoptosis. Further analysis indicated that tumor suppressor p53 was one of the proteins exported from nuclei upon proteasome inhibition, and in the presence of CRM1 inhibitor KPT330, nuclear p53, and expression of its target genes were increased markedly. Moreover, knockdown of p53 significantly reduced the synergistic cytotoxic action of bortezomib and KPT330 on p53 HCT116 cells. In mice, KPT330 markedly augmented the antitumor action of bortezomib against HCT116 xenografts as well as patient-derived xenografts that harbored functional p53. These results indicate that nuclear p53 is a major mediator in the synergistic antitumor effect of bortezomib and KPT330, and provides a rationale for the use of proteasome inhibitor together with nuclear export blocker in the treatment of colorectal cancer. It is conceivable that targeting nuclear exportation may serve as a novel strategy to overcome resistance and raise chemotherapeutic efficacy, especially for the drugs that activate the p53 system. .

Nuclear Export of Ubiquitinated Proteins Determines the Sensitivity of Colorectal Cancer to Proteasome Inhibitor.

Immuno-oncology (I/O) research has intensified significantly in recent years due to the breakthrough development and the regulatory approval of several immune checkpoint inhibitors, leading to the rapid expansion of the new discovery of novel I/O therapies, new checkpoint inhibitors and beyond. However, many I/O questions remain unanswered, including why only certain subsets of patients respond to these treatments, who the responders would be, and how to expand patient response (the conversion of non-responders or maximizing response in partial responders). All of these require relevant I/O experimental systems, particularly relevant preclinical animal models. Compared to other oncology drug discovery, e.g. cytotoxic and targeted drugs, a lack of relevant animal models is a major obstacle in I/O drug discovery, and an urgent and unmet need. Despite the obvious importance, and the fact that much I/O research has been performed using many different animal models, there are few comprehensive and introductory reviews on this topic. This article attempts to review the efforts in development of a variety of such models, as well as their applications and limitations for readers new to the field, particularly those in the pharmaceutical industry.

Experimental animal modeling for immuno-oncology.

Cetuximab has been evaluated as a first-line treatment with conflicting results. The aim of the present study was to investigate the relationship between epidermal growth factor receptor (EGFR) status, and response and survival benefit following cetuximab treatment in gastric cancer (GC). Using 20 patient-derived GC xenograft (PDX) models, the mice (10 mice/model) were randomly assigned into two groups. The control group and treatment group were treated with PBS and cetuximab, respectively. The drug response was evaluated by monitoring tumor growth. Survival benefit was evaluated by comparing the survival curves corresponding to the time for the tumors to reach 600 mm3. Our results revealed that the PDX models treated with cetuximab had better survival than that noted for the non-treated group (P<0.05). The EGFR status was measured by FISH, qPCR, RNAish and immunohistochemistry, respectively. Four cases in the treated group were identified as responsive to cetuximab. EGFR mRNA and protein overexpression were associated with the response to cetuximab (P<0.05). EGFR amplification, mRNA and protein overexpression were associated with prolonged survival in the cetuximab-treated PDX models. Moreover, in the PDX models with EGFR amplification, mRNA or protein overexpression, cetuximab treatment was associated with a better survival compared with that noted in the untreated group in the PDX models (P<0.05), while the survival was not statistically different in the other cases (P>0.05). In conclusion, cetuximab provided survival benefit in the trial. The level of EGFR amplification and overexpression significantly predicted response and survival benefit, particularly the mRNA and protein expression level. A combination of mRNA and protein expression may predict efficacy of cetuximab more efficiently.

EGFR gene status predicts response and survival benefit in a preclinical gastric cancer trial treating patient‑derived xenografts with cetuximab.

The RAF/mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) kinase (MEK)/ERK (RAF/MEK/ERK) signaling cascade serves a prominent role in hepatocellular carcinoma (HCC) proliferation. Sorafenib (BAY 43‑9006) is a potent multikinase inhibitor of RAF kinases and a few receptor tyrosine kinases. Additionally, sorafenib causes apoptosis in a number of human tumor cell lines such as leukemia cell lines. Sorafenib is the first targeted drug to prolong the overall survival of patients with advanced HCC. However, sorafenib activity is less favorable in certain cancers, including sarcomas and melanomas, due to patient insensitivity and drug resistance. In the present study, a novel bi‑aryl urea, N‑(3‑trifluoromethylphenyl)‑N'-(2-methyl-4-(6‑cyclopropanecarboxamido-pyrimidin-4-yl) oxyphenyl) urea (CBI‑5725), is shown to be a potential candidate for the treatment of liver cancer. In the present study, the in vitro activities of CBI‑5725 and sorafenib in PLC/PRF/5 HCC cells were examined and the corresponding in vivo antitumor activities in PLC/PRF/5 human tumor xenografts. An alamar blue assay confirmed that CBI‑5725 was more cytotoxic than sorafenib to PLC/PRF/5 cells, suggesting that CBI‑5725 inhibited tumor cell proliferation more potently than sorafenib. CBI‑5725 inhibited the RAF/MEK/ERK signaling pathway to the same extent as sorafenib. In addition, CBI‑5725 elicited cell cycle arrest in the G2/M phase, while sorafenib did not markedly alter the cell cycle. Furthermore, CBI‑5725 induced apoptosis more strongly than sorafenib in a dose‑dependent manner, which may be attributed to greater caspase‑3 and poly(adenosine 5'‑diphosphate‑ribose) polymerase activation by CBI‑5725. In the PLC/PRF/5 xenograft model, 2 mg/kg CBI‑5725 inhibited tumor growth by 73%. At doses ranging from 6 to 18 mg/kg, CBI‑5725 nearly completely prevented tumor growth. These results imply that the antitumor efficacy of CBI‑5725 in HCC models may result from the suppression of the RAF/MEK/ERK signaling pathway, the induction of cell cycle arrest in the G2/M phase, and the initiation of caspase‑3‑dependent apoptosis. These observations suggested that CBI‑5725 may be a potent novel compound for the treatment of HCC.

Qi-Xang Li

Crown Bioscience Inc.

Immunophenotyping of Orthotopic Homograft (Syngeneic) of Murine Primary KPC Pancreatic Ductal Adenocarcinoma by Flow Cytometry