Epithelial-Mesenchymal Transition Induces Endoplasmic-Reticulum-Stress Response in Human Colorectal Tumor Cells

Tumor cells are stressed by unfavorable environmental conditions like hypoxia or starvation. Driven by the resulting cellular stress tumor cells undergo epithelial-mesenchymal transition. Additionally, cellular stress is accompanied by endoplasmic reticulum-stress which induces an unfolded protein response. It is unknown if epithelial-mesenchymal transition and endoplasmic reticulum-stress are occurring as independent parallel events or if an interrelationship exists between both of them. Here, we show that in colorectal cancer cells endoplasmic reticulum-stress depends on the induction of ZEB-1, which is a main factor of epithelial-mesenchymal transition. In the absence of ZEB-1 colorectal cancer cells cannot mount endoplasmic reticulum-stress as a reaction on cellular stress situations like hypoxia or starvation. Thus, our data suggest that there is a hierarchy in the development of cellular stress which starts with the presence of environmental stress that induces epithelial-mesenchymal transition which allows finally endoplasmic reticulum-stress. This finding highlights the central role of epithelial-mesenchymal transition during the process of tumorigenesis as epithelial-mesenchymal transition is also associated with chemoresistance and cancer stemness. Consequently, endoplasmic reticulum-stress might be a well suited target for chemotherapy of colorectal cancers

The Impact of SMAD4 Loss on Outcome in Patients with Advanced Pancreatic Cancer Treated with Systemic Chemotherapy

The role of the tumor suppressor mothers against decapentaplegic homolog 4 (SMAD4) has not yet been defined in patients (pts) with advanced pancreatic cancer (aPC). This translational research study was designed to evaluate the impact of tumoral SMAD4 loss on clinicopathological parameters and outcome in PC patients receiving palliative chemotherapy. Using immunohistochemistry, we examined SMAD4 expression in tumor tissue of 143 aPC pts treated within completed prospective clinical and biomarker trials. In uni- and multivariate analyses, SMAD4 expression status was correlated to clinicopathological patient characteristics and outcome. At chemotherapy initiation, 128 pts had metastatic PC;most pts (n = 99) received a gemcitabine-based regimen. SMAD4 loss was detected in 92 pts (64%);patient characteristics such as gender, age, tumor grading, disease stage or number of metastatic sites had no significant impact on tumoral SMAD4 status. In univariate analyses, SMAD4 loss had no impact on overall survival (hazard ratio (HR) 1.008, p = 0.656);however, we observed a prolonged progression-free survival (HR 1.565, p = 0.038) in pts with tumoral SMAD4 loss. This finding was confirmed in multivariate analyses (HR 1.790, p = 0.040), but only for gemcitabine-treated pts. In contrast to previous studies in resectable PC, loss of SMAD4 expression was not associated with a negative outcome in patients with advanced PC receiving systemic chemotherapy

Bacterial Lipopolysaccharide as a Negative Predictor of Adjuvant Gemcitabine Efficacy in Pancreatic Cancer

Adjuvant gemcitabine (aGC) is one standard of care after pancreatic ductal adenocarcinoma (PDAC) resection. No biomarker for its efficacy is established. As bacteria mediate gemcitabine resistance, we analyzed whether lipopolysaccharide (LPS) as surrogate for bacterial colonization is prognostic in PDAC patients treated with aGC or without aGC adjuvant gemcitabine. We detected LPS in 86 tumors from 376 patients, which defined a specific microbiome as revealed by 16 s-rRNA-sequencing. In the 230 aGC patients, LPS conferred worse disease-free survival (8.3 vs 13.7 months; hazard ratio = 1.75, 95% confidence interval = 1.22 to 2.49; log-rank P = .002) and overall survival (21.7 vs 28.5 months; hazard ratio = 1.80, 95% confidence interval = 1.23 to 2.57; log-rank P = .001) but not in the 146 naGC patients, which was confirmed in an independent validation cohort (n = 178). LPS may serve as a negative predictor for aGC efficacy in PDAC, which suggests a role for microbiome modification to overcome bacteria-mediated chemotherapy resistance

NGS-guided precision oncology in metastatic breast and gynecological cancer: first experiences at the CCC Munich LMU

PURPOSE Comprehensive genomic profiling identifying actionable molecular alterations aims to enable personalized treatment for cancer patients. The purpose of this analysis was to retrospectively assess the impact of personalized recommendations made by a multidisciplinary tumor board (MTB) on the outcome of patients with breast or gynecological cancers, who had progressed under standard treatment. Here, first experiences of our Comprehensive Cancer Center Molecular Tumor Board are reported. METHODS All patients were part of a prospective local registry. 95 patients diagnosed with metastatic breast cancer or gynecological malignancies underwent extended molecular profiling. From May 2017 through March 2019, the MTB reviewed all clinical cases considering tumor profile and evaluated molecular alterations regarding further diagnostic and therapeutic recommendations. RESULTS 95 patients with metastatic breast or gynecological cancers were discussed in the MTB (68% breast cancer, 20% ovarian cancer, 5% cervical cancer, 3% endometrial cancer and 4% others). Genes with highest mutation rate were PIK3CA and ERBB2. Overall, 34 patients (36%) received a biomarker-based targeted therapy recommendation. Therapeutic recommendations were implemented in nine cases; four patients experienced clinical benefit with a partial response or disease stabilization lasting over 4~months. CONCLUSION In the setting of a multidisciplinary molecular tumor board, a small but clinically meaningful group of breast and gynecological cancer patients benefits from comprehensive genomic profiling. Broad and successful implementation of precision medicine is complicated by patient referral at late stage disease and limited access to targeted agents and early clinical trials. TRIAL REGISTRATION NUMBER 284-10 (03.05.2018)

Switch in KRAS mutational status during an unusual course of disease in a patient with advanced pancreatic adenocarcinoma: implications for translational research

Background: Despite the introduction of novel effective treatment regimens like gemcitabine plus nab-paclitaxel and FOLFIRINOX, pancreatic ductal adenocarcinoma (PDAC) remains one of the most aggressive epithelial tumors. Among the genetic alterations frequently found in PDAC, mutations in the KRAS gene might play a prognostic role regarding overall survival and may also have the potential to predict the efficacy of anti-EGFR treatment. Case presentation: We report the clinical case of a 69 year old Caucasian female that was diagnosed with histologically confirmed locally advanced PDAC with lymph node involvement in August 2010. At the time of first diagnosis, tumor tissue obtained from an open regional lymph node biopsy showed a poorly differentiated adenocarcinoma with a wild type sequence within exon 2 (codon 12/13) of the KRAS gene. The patient initially received single-agent gemcitabine and a subsequent 5-FU-based chemoradiotherapy with a sequential maintenance chemotherapy with oral capecitabine resulting in a long term disease control. Local disease progression occurred in May 2014 and the patient underwent pancreaticoduodenectomy in September 2014. A novel KRAS gene mutation (c. 35G > T, p. G12 V) in exon 2 (codon 12) was detected within the surgical specimen. As of January 2016 the patient is still alive and without evidence of the underlying disease. Conclusions: Specifically in the context of clinical trials and translational research in PDAC a re-assessment of molecular biomarkers, i.e. KRAS, at defined time points (e.g. relapse, disease progression, unusual clinical course) may be indicated in order to detect a potential switch in biomarker status during the course of disease