Regorafenib demonstrated efficacy in patients with metastatic colorectal cancer (mCRC). Lack of predictive biomarkers, potential toxicities and cost-effectiveness concerns highlight the unmet need ...for better patient selection.
Patients with
mutant mCRC with biopsiable metastases were enrolled in this phase II trial. Dynamic contrast-enhanced (DCE) MRI was acquired pretreatment and at day 15 post-treatment. Median values of volume transfer constant (K
), enhancing fraction (EF) and their product KEF (summarised median values of K
× EF) were generated. Circulating tumour (ct) DNA was collected monthly until progressive disease and tested for clonal
mutations by digital-droplet PCR. Tumour vasculature (CD-31) was scored by immunohistochemistry on 70 sequential tissue biopsies.
Twenty-seven patients with paired DCE-MRI scans were analysed. Median KEF decrease was 58.2%. Of the 23 patients with outcome data, >70% drop in KEF (6/23) was associated with higher disease control rate (p=0.048) measured by RECIST V. 1.1 at 2 months, improved progression-free survival (PFS) (HR 0.16 (95% CI 0.04 to 0.72), p=0.02), 4-month PFS (66.7% vs 23.5%) and overall survival (OS) (HR 0.08 (95% CI 0.01 to 0.63), p=0.02). KEF drop correlated with CD-31 reduction in sequential tissue biopsies (p=0.04).
mutant clones decay in ctDNA after 8 weeks of treatment was associated with better PFS (HR 0.21 (95% CI 0.06 to 0.71), p=0.01) and OS (HR 0.28 (95% CI 0.07-1.04), p=0.06).
Combining DCE-MRI and ctDNA predicts duration of anti-angiogenic response to regorafenib and may improve patient management with potential health/economic implications.
We evaluated the efficacy and tolerability of mebeverine, a musculotropic antispasmodic agent, in irritable bowel syndrome (IBS) and compared its usual dosages by meta-analysis. Medical databases and ...all relevant literature were searched from 1965 to June 2009 for any placebo-controlled clinical trials of mebeverine, using search terms such as mebeverine, clinical trials, and IBS. Eight randomized trials met our criteria, including six trials that compared mebeverine with placebo and two that compared mebeverine tablets with capsules. These eight trials included 555 patients randomized to receive either mebeverine or placebo with 352 (63%) women and 203 (37%) men in all subtypes of IBS. The pooled relative risk (RR) for clinical improvement of mebeverine was 1.13 (95% CI: 0.59-2.16, P = 0.7056) and 1.33 (95% CI: 0.92-1.93, P = 0.129) for relief of abdominal pain. The efficacy of mebeverine 200 mg compared to mebeverine 135 mg indicated RRs of 1.12 (95% CI: 0.96-1.3, P = 0.168) for clinical or global improvement and 1.08 (95% CI: 0.87-1.34, P = 0.463) for relief of abdominal pain. Thus, mebeverine is mostly well tolerated with no significant adverse effects; however, its efficacy in global improvement of IBS is not statistically significant.
Previous work utilizing proteomic and immunohistochemical analyses has identified that high levels of acid ceramidase (AC) expression confers a poorer response to neoadjuvant treatment in locally ...advanced rectal cancer. We aimed to assess the radiosensitising effect of biological and pharmacological manipulation of AC and elucidate the underlying mechanism. AC manipulation in three colorectal cancer cell lines (HT29, HCT116 and LIM1215) was achieved using siRNA and plasmid overexpression. Carmofur and a novel small molecular inhibitor (LCL521) were used as pharmacological AC inhibitors. Using clonogenic assays, we demonstrate that an siRNA knockdown of AC enhanced X-ray radiosensitivity across all colorectal cancer cell lines compared to a non-targeting control siRNA, and conversely, AC protein overexpression increased radioresistance. Using CRISPR gene editing, we also generated AC knockout HCT116 cells that were significantly more radiosensitive compared to AC-expressing cells. Similarly, two patient-derived organoid models containing relatively low AC expression were found to be comparatively more radiosensitive than three other models containing higher levels of AC. Additionally, AC inhibition using carmofur and LCL521 in three colorectal cancer cell lines increased cellular radiosensitivity. Decreased AC protein led to significant poly-ADP ribose polymerase-1 (PARP-1) cleavage and apoptosis post-irradiation, which was shown to be executed through a p53-dependent process. Our study demonstrates that expression of AC within colorectal cancer cell lines modulates the cellular response to radiation, and particularly that AC inhibition leads to significantly enhanced radiosensitivity through an elevation in apoptosis. This work further solidifies AC as a target for improving radiotherapy treatment of locally advanced rectal cancer.
Propionic acidemia (PA) is a life-threatening disease caused by the deficiency of a mitochondrial biotin-dependent enzyme known as propionyl coenzyme-A carboxylase (PCC). This enzyme is responsible ...for degrading the metabolic intermediate, propionyl coenzyme-A (PP-CoA), derived from multiple metabolic pathways. Currently, except for drastic surgical and dietary intervention that can only provide partial symptomatic relief, no other form of therapeutic option is available for this genetic disorder. Here, we examine a novel approach in protein delivery by specifically targeting and localizing our protein candidate of interest into the mitochondrial matrix of the cells. In order to test this concept of delivery, we have utilized cell penetrating peptides (CPPs) and mitochondria targeting sequences (MTS) to form specific fusion PCC protein, capable of translocating and localizing across cell membranes. In vitro delivery of our candidate fusion proteins, evaluated by confocal images and enzymatic activity assay, indicated effectiveness of this strategy. Therefore, it holds immense potential in creating a new paradigm in site-specific protein delivery and enzyme replacement therapeutic for PA.
Anti-EGFR mAbs are effective in the treatment of metastatic colorectal cancer (mCRC) patients.
status and tumor location (sidedness) are predictive markers of patients' response to anti-EGFR mAbs. ...Recently, low miR-31-3p expression levels have been correlated with clinical benefit from the anti-EGFR mAb cetuximab. Here, we aimed to validate the predictive power of miR-31-3p in a prospective cohort of chemorefractory mCRC patients treated with single-agent anti-EGFR mAbs.
miR-31-3p was tested by
hybridization (ISH) in 91 pretreatment core biopsies from metastatic deposits of 45 patients with mCRC. Sequential tissue biopsies obtained before treatment, at the time of partial response, and at disease progression were tested to monitor changes in miR-31-3p expression overtreatment. miR-31-3p expression, sidedness, and
status in pretreatment cell-free DNA were combined in multivariable regression models to assess the predictive value of each variable alone or in combination.
Patients with low miR-31-3p expression in pretreatment biopsies showed better overall response rate, as well as better progression-free survival and overall survival, compared to those with high miR-31-3p expression. The prognostic effect of miR-31-3p was independent from age, gender, and sidedness. No significant changes in the expression of miR-31-3p were observed when sequential tissue biopsies were tested in long-term or poor responders to anti-EGFR mAbs. miR-31-3p scores were similar when pretreatment biopsies were compared with treatment-naïve archival tissues (often primary colorectal cancer).
Our study validates the role of miR-31-3p as potential predictive biomarker of selection for anti-EGFR mAbs.
We evaluated the eff icacy and tolerability of mebeverine, a musculotropic antispasmodic agent, in irritable bowel syndrome (IBS) and compared its usual dosages by meta-analysis. Medical databases ...and all relevant literature were searched from 1965 to June 2009 for any placebo-controlled clinical trials of mebeverine, using search terms such as mebeverine, clinical trials, and IBS. Eight randomized trials met our criteria, including six trials that compared mebeverine with placebo and two that compared mebe...
Sequential profiling of plasma cell-free (cf)DNA holds immense promise for early detection of patient relapse. However, how to exploit the predictive power of cfDNA as a liquid biopsy in the clinic ...remains unclear. RAS pathway aberrations can be tracked in cfDNA to monitor resistance to anti-epidermal growth factor receptor (EGFR) monoclonal antibodies in metastatic colorectal cancer patients. In this prospective phase II clinical trial of single-agent cetuximab in
RAS
wild-type patients, we combine genomic profiling of serial cfDNA and matched sequential tissue biopsies with imaging and mathematical modelling of cancer evolution. We show that a significant proportion of patients defined as
RAS
wild-type based on diagnostic tissue analysis harbour aberrations in RAS pathway in pre-treatment cfDNA and, in fact, do not benefit from EGFR inhibition. We demonstrate that primary and acquired resistance to cetuximab are often of polyclonal nature, and these dynamics can be observed in tissue and plasma. Furthermore, evolutionary modelling combined with frequent serial sampling of cfDNA allowed predicting the expected waiting time to treatment failure in individual patients. This study demonstrates how integrating frequently-sampled longitudinal liquid biopsies with a mathematical framework of tumour evolution allows individualised quantitative forecasting of relapse, providing novel opportunities for adaptive personalised therapies.
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