Irinotecan-Induced Dysarthria

Colorectal carcinomas are among the most common tumor types and are generally treated with palliative chemotherapy in case of metastatic disease. Here, we describe the case of a 46-year-old patient with metastatic rectal carcinoma who received second-line therapy with irinotecan and developed isolated transient dysarthria (with normal MR imaging of the brain) following each administration of irinotecan. Neurological and logopedical evaluation revealed that the dysarthria predominantly resulted from a reduced capacity in fine-tuning of motor functions of the tip of the tongue and a minimal reduction in the power of speech at labiodental contact. As hypoglossal nerve activity has been reported to be especially susceptible to cholinergic stimulation and irinotecan can cause cholinergic side effects by binding to and inactivating acetylcholinesterase, we suspect this mechanism to be responsible for irinotecan-induced dysarthria

NDUFA4L2 reduces mitochondrial respiration resulting in defective lysosomal trafficking in clear cell renal cell carcinoma

In clear cell renal cell carcinoma (ccRCC), activation of hypoxic signaling induces NADH dehydrogenase (ubiquinone) 1 alpha subcomplex, 4-like 2 (NDUFA4L2) expression. Over 90% of ccRCCs exhibit overexpression of NDUFA4L2, which we previously showed contributes to ccRCC proliferation and survival. The function of NDUFA4L2 in ccRCC has not been fully elucidated. NDUFA4L2 was reported to reduce mitochondrial respiration via mitochondrial complex I inhibition. We found that NDUFA4L2 expression in human ccRCC cells increases the extracellular acidification rate, indicative of elevated glycolysis. Conversely, NDUFA4L2 expression in non-cancerous kidney epithelial cells decreases oxygen consumption rate while increasing extracellular acidification rate, suggesting that a Warburg-like effect is induced by NDUFA4L2 alone. We performed mass-spectrometry (MS)-based proteomics of NDUFA4L2 associated complexes. Comparing RCC4-P (parental) ccRCC cells with RCC4 in which NDUFA4L2 is knocked out by CRISPR-Cas9 (RCC4-KO-643), we identified 3,215 proteins enriched in the NDUFA4L2 immunoprecipitates. Among the top-ranking pathways were "Metabolic Reprogramming in Cancer" and "Glycolysis Activation in Cancer (Warburg Effect)." We also show that NDUFA4L2 enhances mitochondrial fragmentation, interacts with lysosomes, and increases mitochondrial-lysosomal associations, as assessed by high-resolution fluorescence microscopy and live cell imaging. We identified 161 lysosomal proteins, including Niemann-Pick Disease Type C Intracellular Cholesterol Transporters 1 and 2 (NPC1, NPC2), that are associated with NDUFA4L2 in RCC4-P cells. RCC4-P cells have larger and decreased numbers of lysosomes relative to RCC4 NDUFA4L2 knockout cells. These findings suggest that NDUFA4L2 regulates mitochondrial-lysosomal associations and potentially lysosomal size and abundance. Consequently, NDUFA4L2 may regulate not only mitochondrial, but also lysosomal functions in ccRCC

Lactic Acidosis in Prostate Cancer: Consider the Warburg Effect

Lactic acidosis is a commonly observed clinical condition that is associated with a poor prognosis, especially in malignancies. We describe a case of an 81-year-old patient who presented with symptoms of tachypnea and general discomfort. Arterial blood gas analysis showed a high anion gap acidosis with a lactate level of 9.5 mmol/L with respiratory compensation. CT scanning showed no signs of pulmonary embolism or other causes of impaired tissue oxygenation. Despite treatment with sodium bicarbonate, the patient developed an adrenalin-resistant cardiac arrest, most likely caused by the acidosis. Autopsy revealed Gleason score 5 + 5 metastatic prostate cancer as the most probable cause of the lactic acidosis. Next-generation sequencing indicated a nonsense mutation in the TP53 gene (887delA) and an activating mutation in the PIK3CA gene (1634A>G) as candidate molecular drivers. This case demonstrates the prevalence and clinical relevance of metabolic reprogramming, frequently referred to as “the Warburg effect,” in patients with prostate cancer

Novel drugs that target the metabolic reprogramming in renal cell cancer

Molecular profiling studies of tumor tissue from patients with clear cell renal cell cancer (ccRCC) have revealed extensive metabolic reprogramming in this disease. Associations were found between metabolic reprogramming, histopathologic Fuhrman grade, and overall survival of patients. Large-scale genomics, proteomics, and metabolomic analyses have been performed to identify the molecular players in this process. Genes involved in glycolysis, the pentose phosphate pathway, glutamine metabolism, and lipogenesis were found to be upregulated in renal cell cancer (RCC) specimens as compared to normal tissue. Preclinical research indicates that mutations in VHL, FBP1, and the PI3K-AKT-mTOR pathway drives aerobic glycolysis through transcriptional activation of the hypoxia-inducible factors (HIF). Mechanistic studies revealed glutamine as an important source for de novo fatty acid synthesis through reductive carboxylation. Amplification of MYC drives reductive carboxylation. In this review, we present a detailed overview of the metabolic changes in RCC in conjunction with potential novel therapeutics. We discuss preclinical studies that have investigated targeted agents that interfere with various aspects of tumor cell metabolism and emphasize their impact specifically on glycolysis, lipogenesis, and tumor growth. Furthermore, we describe a number of phase 1 and 2 clinical trials that have been conducted with these agents

Selection of Protein Kinase Inhibitors Based on Tumor Tissue Kinase Activity Profiles in Patients with Refractory Solid Malignancies: An Interventional Molecular Profiling Study

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Analysis of AKT and ERK1/2 protein kinases in extracellular vesicles isolated from blood of patients with cancer

Background: Extracellular vesicles (EVs) are small nanometre-sized vesicles that are circulating in blood. They are released by multiple cells, including tumour cells. We hypothesized that circulating EVs contain protein kinases that may be assessed as biomarkers during treatment with tyrosine kinase inhibitors. Methods: EVs released by U87 glioma cells, H3255 and H1650 non-small-cell lung cancer (NSCLC) cells were profiled by tandem mass spectrometry. Total AKT/protein kinase B and extracellular signal regulated kinase 1/2 (ERK1/2) levels as well as their relative phosphorylation were measured by western blot in isogenic U87 cells with or without mutant epidermal growth factor receptor (EGFRvIII) and their corresponding EVs. To assess biomarker potential, plasma samples from 24 healthy volunteers and 42 patients with cancer were used. Results: In total, 130 different protein kinases were found to be released in EVs including multiple drug targets, such as mammalian target of rapamycin (mTOR), AKT, ERK1/2, AXL and EGFR. Overexpression of EGFRvIII in U87 cells results in increased phosphorylation of EGFR, AKT and ERK1/2 in cells and EVs, whereas a decreased phosphorylation was noted upon treatment with the EGFR inhibitor erlotinib. EV samples derived from patients with cancer contained significantly more protein (p=0.0067) compared to healthy donors. Phosphorylation of AKT and ERK1/2 in plasma EVs from both healthy donors and patients with cancer was relatively low compared to levels in cancer cells. Preliminary analysis of total AKT and ERK1/2 levels in plasma EVs from patients with NSCLC before and after sorafenib/metformin treatment (n=12) shows a significant decrease in AKT levels among patients with a favourable treatment response (p<0.005). Conclusion: Phosphorylation of protein kinases in EVs reflects their phosphorylation in tumour cells. Total AKT protein levels may allow monitoring of kinase inhibitor responses in patients with cancer

Evaluation of a tyrosine kinase peptide microarray for tyrosine kinase inhibitor therapy selection in cancer

Personalized cancer medicine aims to accurately predict the response of individual patients to targeted therapies, including tyrosine kinase inhibitors (TKIs). Clinical implementation of this concept requires a robust selection tool. Here, using both cancer cell lines and tumor tissue from patients, we evaluated a high-throughput tyrosine kinase peptide substrate array to determine its readiness as a selection tool for TKI therapy. We found linearly increasing phosphorylation signal intensities of peptides representing kinase activity along the kinetic curve of the assay with 7.5-10 μg of lysate protein and up to 400 μM adenosine triphosphate (ATP). Basal kinase activity profiles were reproducible with intra- and inter-experiment coefficients of variation of <15% and <20%, respectively. Evaluation of 14 tumor cell lines and tissues showed similar consistently high phosphorylated peptides in their basal profiles. Incubation of four patient-derived tumor lysates with the TKIs dasatinib, sunitinib, sorafenib and erlotinib primarily caused inhibition of substrates that were highly phosphorylated in the basal profile analyses. Using recombinant Src and Axl kinase, relative substrate specificity was demonstrated for a subset of peptides, as their phosphorylation was reverted by co-incubation with a specific inhibitor. In conclusion, we demonstrated robust technical specifications of this high-throughput tyrosine kinase peptide microarray. These features required as little as 5-7 μg of protein per sample, facilitating clinical implementation as a TKI selection tool. However, currently available peptide substrates can benefit from an enhancement of the differential potential for complex samples such as tumor lysates. We propose that mass spectrometry-based phosphoproteomics may provide such an enhancement by identifying more discriminative peptides

Indications and Outcomes for Deferred Cytoreductive Nephrectomy Following Immune Checkpoint Inhibitor Combination Therapy: Can Systemic Therapy be Withdrawn in Patients with No Evidence of Disease?

Background: Upfront cytoreductive nephrectomy (CN) is no longer the standard of care for patients with metastastic renal cell carcinoma (mRCC) with intermediate or poor prognosis according to the International mRCC Database Consortium categories. Objective: To investigate indications for CN following first-line ipilimumab-nivolumab, and assess management and outcomes for patients achieving no evidence of disease (NED) after CN. Design, setting, and participants: This was a retrospective cohort study among 125 patients with synchronous mRCC who received ipilimumab-nivolumab treatment between March 2019 and June 2022 at four European centres. At one of the four centres, nivolumab was stopped following NED. Outcome measurements and statistical analysis: We measured complete response of metastases (mCR) according to Response Evaluation Criteria in Solid Tumours 1.1; near-complete response of mestastases (mnCR) was defined as a >80% reduction in cumulative metastatic volume. Treatment-free survival (TFS), disease-free survival (DFS), progression-free survival (PFS), and cancer-specific survival (CSS) were determined. Results and limitations: At median follow-up of 25 mo, 23/125 patients (18%) had undergone deferred CN. Of 26 patients (21%) with mCR or mnCR, 19 (73%) underwent CN to achieve NED, of whom 11 (58%) discontinued nivolumab, with median TFS of 21 mo. For patients who continued (n = 8, 42%) versus discontinued nivolumab following NED, 2-yr DFS was 83% versus 60% (p = 0.675) and 3-yr CSS was 100% versus 70% (p = 0.325). Four patients underwent CN because of a dissociated response of the primary tumour and were still alive at median follow-up of 5 mo. Conclusions: CN can result in NED, durable DFS, and substantial time off systemic therapy. More collaborative data are required to ascertain the benefits of treatment discontinuation versus oncologic safety. Patient summary: In our study using real-world data, 18% of patients treated with immunotherapy underwent deferred kidney surgery. The majority were free of disease after 3 years. Half of the patients who stopped immunotherapy after surgery have been off therapy for 21 months or longer. Larger studies are needed to investigate the effect of kidney surgery and discontinuation of immunotherapy on survival