Inhibition of Rho-Associated Kinase 1/2 Attenuates Tumor Growth in Murine Gastric Cancer

Abstract

Gastric cancer (GC) remains a malignant disease with high mortality. Patients are frequently diagnosed in advanced stages where survival prognosis is poor. Thus, there is high medical need to find novel drug targets and treatment strategies. Recently, the comprehensive molecular characterization of GC subtypes revealed mutations in the small GTPase RHOA as a hallmark of diffuse-type GC. RHOA activates RHO-associated protein kinases (ROCK1/2) which regulate cell contractility, migration and growth and thus may play a role in cancer. However, therapeutic benefit of RHO-pathway inhibition in GC has not been shown so far. The ROCK1/2 inhibitor 1-(5-isoquinoline sulfonyl)-homopiperazine (HA-1077, fasudil) is approved for cerebrovascular bleeding in patients. We therefore investigated whether fasudil (i.p., 10 mg/kg per day, 4 times per week, 4 weeks) inhibits tumor growth in a preclinical model of GC. Fasudil evoked cell death in human GC cells and reduced the tumor size in the stomach of CEA424-SV40 TAg transgenic mice. Small animal PET/CT confirmed preclinical efficacy. Mass spectrometry imaging identified a translatable biomarker for mouse GC and suggested rapid but incomplete in situ distribution of the drug to gastric tumor tissue. RHOA expression was increased in the neoplastic murine stomach compared with normal non-malignant gastric tissue, and fasudil reduced (auto) phosphorylation of ROCK2 at THR249 in vivo and in human GC cells in vitro. In sum, our data suggest that RHO-pathway inhibition may constitute a novel strategy for treatment of GC and that enhanced distribution of future ROCK inhibitors into tumor tissue may further improve efficacy.

FLI1 Exonic Circular RNAs as a Novel Oncogenic Driver to Promote Tumor Metastasis in Small Cell Lung Cancer

“…ROCK-1 functions as an oncogene and is overexpressed in many tumors (29), including lung cancers. Its expression is not only associated with migration, invasion, and metastasis (31,32), but is also closely related with pulmonary fibrosis (33,34) and lung diseases (35). The oncogenic activity of ROCK-1 is controlled by miR584 (26).…”

Spatial Distribution of Endogenous Tissue Protease Activity in Gastric Carcinoma Mapped by MALDI Mass Spectrometry Imaging

“…MALDI-TOF and MALDI-FT-ICR Mass Spectrometry Imaging-MALDI-TOF MSI with DHB matrix was performed as outlined (14). Porcine tissues were analyzed using an ultrafleXtreme MALDI-TOF/ TOF instrument (Bruker Daltonik) in reflector positive mode and a mass range of m/z 500 -2500.…”

“…The segmentation was performed based on the m/z segment of 798.54 Ϯ 5 and 798.54 Ϯ 0.05 for the TOF and FT-ICR data sets, respectively. In that mass range, the lipid PC(34:1)ϩK ϩ with m/z 798.54, known to be enriched in gastric tumor in this mouse model, is present (14). No pre-processing was performed on the imported raw data.…”

“…Sample preparation for MALDI-MS imaging is comparatively fast and, hence, it is of increasing interest for clinical pathology (9,10). MSI is frequently used for analysis of the in situ distribution of proteins (11,12), lipids (13,14), drugs (14), as well as peptides (15), and N-glycans (16,17). A recent study with a neuropeptide, dynorphin, spotted onto rat brain slices suggested that it may be possible to detect the levels of substrate and peptide bioconversion products simultaneously by MSI (18).…”

Quantitative Mass Spectrometry Imaging Reveals Mutation Status-independent Lack of Imatinib Penetration into Liver Metastases of Gastrointestinal Stromal Tumors

“…Slides were stored in a desiccator at room temperature for one hour to allow drying of the IS. For positive-ion mode measurements, five layers (flow rates of 10, 15, 3 × 20 μL/min) of 2,5-Dihydroxybenzoic acid (DHB) matrix (60 mg/mL in 50% acetonitrile, 0.5% Trifluoroacetic acid) were subsequently sprayed onto the tissue at 300 mm/min as described previously (27).…”