Probes for INS

 Background: ASPM is a newly reported stem cell marker and plays important roles in mitosis, cell cycle and tumorigenesis. It links with poor clinical prognosis in various tumors. However, the clinical significance of ASPM in colonic adenocarcinoma (CA) has not been fully studied. The purpose of this study was to investigate if ASPM is correlated with the clinicopathological features of CA. Methods: Primary CA tissue, adenoma and the matched normal mucosa from 99 patients, were detected using immunohistochemical analysis by primary antibodies against ASPM. Meanwhile, 20 CAs and 20 liver metastatic cases were examined by RNA in situ hybridization (RNAscope). To assess the clinical relevance of ASPM, we analyzed the survival follow-up information. Results: ASPM was found only in single cells in the base of normal colon mucosal crypts. But the expression of ASPM was detected high in colonic adenomas (49.5%, 49/99), and significantly higher in CA (56.6%, 56/ 99, P<0.001). In CAs, ASPM expression was more intense in stage III and IV than II and I stage patients (P=0.03), and positively correlated with lymph node metastasis (P=0.03), but not with the age at diagnosis, gender and histological grade (P>0.05). We also analyzed the survival follow-up information, the data showed that ASPM-positive expression was correlated with a shorter disease-free survival (DFS) time, the average DFS time of patients with ASPM positive and negative expression was 62.79±2.32 months and 71.30±2.72 months, respectively, and there was no statistical significance between the two groups (P>0.05). The results of ASPM mRNA measurement by RNAscope revealed ASPM mRNA expression was higher in primary CA than that in metastatic liver CA (P<0.001). Conclusions: ASPM might play an important role in colonic carcinogenesis and be a potential marker in predicting prognosis of CA. 

The fibroblast growth factor receptor FGFR2 is overexpressed in a variety of solid tumors, including breast, gastric and ovarian tumors, where it offers a potential therapeutic target. In this study, we present evidence of the preclinical efficacy of BAY 1187982, a novel antibody-drug conjugate (ADC). It consists of a fully human FGFR2 monoclonal antibody (mAb BAY 1179470), which is specific for the FGFR2 isoforms FGFR2-IIIb and FGFR2-IIIc, conjugated through a non-cleavable linker to a novel derivative of the microtubule-disrupting cytotoxic drug auristatin (FGFR2-ADC). In FGFR2-expressing cancer cell lines, this FGFR2-ADC exhibited potency in the low nM to sub-nM range and was more than 100-fold selective against FGFR2-negative cell lines. High expression levels of FGFR2 in cells correlated with efficient internalization, efficacy and cytotoxic effects in vitro. Pharmacokinetic analyses in mice bearing FGFR2-positive NCI-H716 tumors indicated that the toxophore metabolite of FGFR2-ADC was enriched more than 30-fold in tumors compared to healthy tissues. Efficacy studies demonstrated that FGFR2-ADC treatment leads to a significant tumor growth inhibition or tumor regression of cell line-based or patient-derived xenograft models of human gastric or breast cancer. Further, FGFR2 amplification or mRNA overexpression predicted high efficacy in both of these types of in vivo model systems. Taken together, our results strongly support the clinical evaluation of BAY 1187982 in cancer patients, and a Phase I study (NCT02368951) has been initiated.

Alterations in genes that regulate brain size may contribute to both microcephaly and brain tumor formation. Here, we report that Aspm, a gene that is mutated in familial microcephaly, regulates postnatal neurogenesis in the cerebellum and supports the growth of medulloblastoma, the most common malignant pediatric brain tumor. Cerebellar granule neuron progenitors (CGNPs) express Aspm when maintained in a proliferative state by sonic hedgehog (Shh) signaling, and Aspm is expressed in Shh-driven medulloblastoma in mice. Genetic deletion of Aspm reduces cerebellar growth, while paradoxically increasing the mitotic rate of CGNPs. Aspm-deficient CGNPs show impaired mitotic progression, altered patterns of division orientation and differentiation, and increased DNA damage, which causes progenitor attrition through apoptosis. Deletion of Aspm in mice with Smo-induced medulloblastoma reduces tumor growth and increases DNA damage. Co-deletion of Aspm and either of the apoptosis regulators Bax or Trp53 (also known as p53) rescues the survival of neural progenitors and reduces the growth restriction imposed by Aspm deletion. Our data show that Aspm functions to regulate mitosis and to mitigate DNA damage during CGNP cell division, causes microcephaly through progenitor apoptosis when mutated, and sustains tumor growth in medulloblastoma.

Abstract

Background

Fibroblast growth factor receptor (FGFR2) has been proposed as a target in gastric cancer. However, appropriate methods to select patients for anti-FGFR2 therapies have not yet been established.

Methods

We used in situ techniques to investigate FGFR2 mRNA expression and gene amplification in a large cohort of 1036 Japanese gastric cancer patients. FGFR2 mRNA expression was determined by RNAscope. FGFR2 gene amplification was determined by dual-color in situ hybridization (DISH).

Results

We successfully analyzed 578 and 718 samples by DISH and RNAscope, respectively; 2% (12/578) showed strong FGFR2 gene amplification (FGFR2:CEN10 >10); moderate FGFR2gene amplification (FGFR2:CEN10 <10; ≥2) was detected in 8% (47/578); and high FGFR2 mRNA expression of score 4 (>10 dots/cell and >10% of positive cells with dot clusters under a 20× objective) was seen in 4% (29/718). For 468 samples, both mRNA and DISH data were available. FGFR2 mRNA expression levels were associated with gene amplification; FGFR2 mRNA levels were highest in the highly amplified samples (n = 12). All highly amplified samples showed very strong FGFR2 mRNA expression (dense clusters of the signal visible under a 1× objective). Patients with very strong FGFR2 mRNA expression showed more homogeneous FGFR2 mRNA expression compared to patients with lower FGFGR2 mRNA expression. Gastric cancer patients with tumors that had an FGFR2 mRNA expression score of 4 had shorter RFS compared with score 0–3 patients.

Conclusion

RNAscope and DISH are suitable methods to evaluate FGFR2 status in gastric cancer. Formalin-fixed paraffin-embedded (FFPE) tissue slides allowed evaluation of the intratumor heterogeneity of these FGFR2 biomarkers.