Atezolizumab monotherapy versus chemotherapy in untreated locally advanced or metastatic urothelial carcinoma (IMvigor130): final overall survival analysis from a randomised, controlled, phase 3 study.

BACKGROUND: The primary analysis of IMvigor130 showed a significant progression-free survival benefit with first-line atezolizumab plus platinum-based chemotherapy (group A) versus placebo plus platinum-based chemotherapy (group C) in patients with locally advanced or metastatic urothelial cancer. However, this finding did not translate into significant overall survival benefit for group A versus group C at the final analysis, precluding formal statistical testing of outcomes with atezolizumab monotherapy (group B) versus group C. Here we report the final overall survival results for group B versus group C; this report is descriptive and should be considered exploratory due to the study's statistical design. METHODS: In this global, partially blinded, randomised, controlled, phase 3 study, patients (aged ≥18 years) who had locally advanced or metastatic urothelial cancer previously untreated in the metastatic setting and Eastern Cooperative Oncology Group performance status of 0-2 were enrolled at 221 hospitals and oncology centres in 35 countries. Patients were randomly assigned (1:1:1), using a permuted block method (block size of six) and an interactive voice and web response system, stratified by PD-L1 status, Bajorin score, and investigator's choice of platinum-based chemotherapy, to receive either atezolizumab plus platinum-based chemotherapy (group A), atezolizumab alone (group B), or placebo plus platinum-based chemotherapy (group C). Sponsors, investigators, and patients were masked to assignment to atezolizumab or placebo in group A and group C; atezolizumab monotherapy in group B was open label. For groups B and C, atezolizumab (1200 mg) or placebo was administered intravenously every 3 weeks. Chemotherapy involved 21-day cycles of gemcitabine (1000 mg/m2 body surface area on day 1 and day 8 of each cycle) plus the investigator's choice of carboplatin (area under the curve 4·5 mg/mL per min or 5 mg/mL per min) or cisplatin (70 mg/m2 body surface area), administered intravenously. Co-primary endpoints were progression-free survival and overall survival in group A versus group C, and overall survival in group B versus group C, tested hierarchically, in the intention-to-treat (ITT) population, and then the populations with high PD-L1 tumour expression (immune cell [IC] expression score of IC2/3) if the results from group A versus group C were significant. Here, we report the co-primary endpoint of overall survival for group B versus group C in the ITT and IC2/3 populations. The ITT population for this analysis comprised concurrently enrolled patients in groups B and C who were randomly assigned to treatment. For the safety analysis, all patients enrolled in group B and group C who received any study treatment were included. The trial is registered with ClinicalTrials.gov, NCT02807636, and is active but no longer recruiting. FINDINGS: Between July 15, 2016, and July 20, 2018, 1213 patients were enrolled and randomly assigned to treatment, of whom 362 patients were assigned to group B and 400 to group C, of whom 360 and 359, respectively, were enrolled concurrently (ITT population). 543 (76%) of 719 patients were male, 176 (24%) were female, and 534 (74%) were White. As of data cutoff (Aug 31, 2022), after a median follow-up of 13·4 months (IQR 6·2-30·8), median overall survival was 15·2 months (95% CI 13·1-17·7; 271 deaths) in group B and 13·3 months (11·9-15·6; 275 deaths) in group C (stratified hazard ratio 0·98 [95% CI 0·82-1·16]). The most common grade 3-4 treatment-related adverse events were anaemia (two [1%] in patients who received atezolizumab monotherapy vs 133 [34%] in those who received placebo plus chemotherapy), neutropenia (one [<1%] vs 115 [30%]), decreased neutrophil count (0 vs 95 [24%]), and decreased platelet count (one [<1%] vs 92 [24%]). Serious adverse events occurred in 163 (46%) patients versus 196 (50%). Treatment-related deaths occurred in three (1%; n=1 each, pneumonia, interstitial lung disease, large intestinal obstruction) patients who received atezolizumab monotherapy and four (1%; n=1 each, diarrhoea, febrile neutropenia, unexplained death, toxic hepatitis) who received placebo plus chemotherapy. INTERPRETATION: The final analysis from IMvigor130 did not show a significant improvement in overall survival with first-line atezolizumab monotherapy compared with platinum-based chemotherapy in the intention-to-treat population. The safety profile of atezolizumab monotherapy remained acceptable after extended follow-up, with no new safety signals. FUNDING: F Hoffmann-La Roche.

Insulin receptor loss impairs mammary tumorigenesis in mice.

Breast cancer (BC) prognosis and outcome are adversely affected by obesity. Hyperinsulinemia, common in the obese state, is associated with higher risk of death and recurrence in BC. Up to 80% of BCs overexpress the insulin receptor (INSR), which correlates with worse prognosis. INSR's role in mammary tumorigenesis was tested by generating MMTV-driven polyoma middle T (PyMT) and ErbB2/Her2 BC mouse models, respectively, with coordinate mammary epithelium-restricted deletion of INSR. In both models, deletion of either one or both copies of INSR leads to a marked delay in tumor onset and burden. Longitudinal phenotypic characterization of mouse tumors and cells reveals that INSR deletion affects tumor initiation, not progression and metastasis. INSR upholds a bioenergetic phenotype in non-transformed mammary epithelial cells, independent of its kinase activity. Similarity of phenotypes elicited by deletion of one or both copies of INSR suggest a dose-dependent threshold for INSR impact on mammary tumorigenesis.

Ca2+ signaling regulates ecmB expression, cell differentiation and slug regeneration in Dictyostelium.

Ca(2+) regulates cell differentiation and morphogenesis in a diversity of organisms and dysregulation of Ca(2+) signal transduction pathways leads to many cellular pathologies. In Dictyostelium Ca(2+) induces ecmB expression and stalk cell differentiation in vitro. Here we have analyzed the pattern of ecmB expression in intact and bisected slugs and the effect of agents that affect Ca(2+) levels or antagonize calmodulin (CaM) on this expression pattern. We have shown that Ca(2+) and CaM regulate ecmB expression and pstAB/pstB cell differentiation in vivo. Agents that increase intracellular Ca(2+) levels increased ecmB expression and/or pstAB and pstB cell differentiation, while agents that decrease intracellular Ca(2+) or antagonize CaM decreased it. In isolated slug tips agents that affect Ca(2+) levels and antagonize CaM had differential effect on ecmB expression and cell differentiation in the anterior versus posterior zones. Agents that increase intracellular Ca(2+) levels increased the number of ecmB expressing cells in the anterior region of slugs, while agents that decrease intracellular Ca(2+) levels or antagonize CaM activity increased the number of ecmB expressing cells in the posterior. We have also demonstrated that agents that affect Ca(2+) levels or antagonize CaM affect cells motility and regeneration of shape in isolated slug tips and backs and regeneration of tips in isolated slug backs. To our knowledge, this is the first study detailing the pattern of ecmB expression in regenerating slugs as well as the role of Ca(2+) and CaM in the regeneration process and ecmB expression.

Colchicine affects cell motility, pattern formation and stalk cell differentiation in Dictyostelium by altering calcium signaling.

Previous work, verified here, showed that colchicine affects Dictyostelium pattern formation, disrupts morphogenesis, inhibits spore differentiation and induces terminal stalk cell differentiation. Here we show that colchicine specifically induces ecmB expression and enhances accumulation of ecmB-expressing cells at the posterior end of multicellular structures. Colchicine did not induce a nuclear translocation of DimB, a DIF-1 responsive transcription factor in vitro. It also induced terminal stalk cell differentiation in a mutant strain that does not produce DIF-1 (dmtA-) and after the treatment of cells with DIF-1 synthesis inhibitor cerulenin (100 µM). This suggests that colchicine induces the differentiation of ecmB-expressing cells independent of DIF-1 production and likely through a signaling pathway that is distinct from the one that is utilized by DIF-1. Depending on concentration, colchicine enhanced random cell motility, but not chemotaxis, by 3-5 fold (10-50 mM colchicine, respectively) through a Ca(2+)-mediated signaling pathway involving phospholipase C, calmodulin and heterotrimeric G proteins. Colchicine's effects were not due to microtubule depolymerization as other microtubule-depolymerizing agents did not have these effects. Finally normal morphogenesis and stalk and spore cell differentiation of cells treated with 10 mM colchicine were rescued through chelation of Ca2+ by BAPTA-AM and EDTA and calmodulin antagonism by W-7 but not PLC inhibition by U-73122. Morphogenesis or spore cell differentiation of cells treated with 50 mM colchicine could not be rescued by the above treatments but terminal stalk cell differentiation was inhibited by BAPTA-AM, EDTA and W-7, but not U-73122. Thus colchicine disrupts morphogenesis and induces stalk cell differentiation through a Ca(2+)-mediated signaling pathway involving specific changes in gene expression and cell motility.

Bestatin inhibits cell growth, cell division, and spore cell differentiation in Dictyostelium discoideum.

Bestatin methyl ester (BME) is an inhibitor of Zn(2+)-binding aminopeptidases that inhibits cell proliferation and induces apoptosis in normal and cancer cells. We have used Dictyostelium as a model organism to study the effects of BME. Only two Zn(2+)-binding aminopeptidases have been identified in Dictyostelium to date, puromycin-sensitive aminopeptidase A and B (PsaA and PsaB). PSA from other organisms is known to regulate cell division and differentiation. Here we show that PsaA is differentially expressed throughout growth and development of Dictyostelium, and its expression is regulated by developmental morphogens. We present evidence that BME specifically interacts with PsaA and inhibits its aminopeptidase activity. Treatment of cells with BME inhibited the rate of cell growth and the frequency of cell division in growing cells and inhibited spore cell differentiation during late development. Overexpression of PsaA-GFP (where GFP is green fluorescent protein) also inhibited spore cell differentiation but did not affect growth. Using chimeras, we have identified that nuclear versus cytoplasmic localization of PsaA affects the choice between stalk or spore cell differentiation pathway. Cells that overexpressed PsaA-GFP (primarily nuclear) differentiated into stalk cells, while cells that overexpressed PsaAΔNLS2-GFP (cytoplasmic) differentiated into spores. In conclusion, we have identified that BME inhibits cell growth, division, and differentiation in Dictyostelium likely through inhibition of PsaA.

Dictyostelium puromycin-sensitive aminopeptidase A is a nucleoplasmic nucleomorphin-binding protein that relocates to the cytoplasm during mitosis.

Nucleomorphin (NumA1) is a nucleolar/nucleoplasmic protein linked to cell cycle in Dictyostelium. It interacts with puromycin-sensitive aminopeptidase A (PsaA) which in other organisms is a Zn(2+)-metallopeptidase thought to be involved in cell cycle progression and is involved in several human diseases. Here, we have shown that Dictyostelium PsaA contains domains characteristic of the M1 family of Zn(2+)-metallopeptidases: a GAMEN motif and a Zn(2+)-binding domain. PsaA colocalized with NumA1 in the nucleoplasm in vegetative cells and was also present to a lesser extent in the cytoplasm. The same localization pattern was observed in cells from slugs, however, in fruiting bodies PsaA was only detected in spore nuclei. During mitosis PsaA redistributed mainly throughout the cytoplasm. It possesses a functional nuclear localization signal ((680)RKRF(683)) necessary for nuclear entry. To our knowledge, this is the first nuclear localization signal identified in a Psa from any organism. Treatment with Ca(2+) chelators or calmodulin antagonists indicated that neither Ca(2+) nor calmodulin is involved in PsaA localization. These results are interpreted in terms of the inter-relationship between NumA1 and PsaA in cell function in Dictyostelium.

Determining time of death: temperature-dependent postmortem changes in calcineurin A, MARCKS, CaMKII, and protein phosphatase 2A in mouse.

While the determination of postmortem interval (PMI) is a crucial and fundamental step in any death investigation, the development of appropriate biochemical methods for PMI estimation is still in its infancy. This study focused on the temperature-dependent postmortem degradation of calcineurin A (CnA), calmodulin-dependent kinase II (CaMKII), myristoylated alanine-rich C-kinase substrate (MARCKs), and protein phosphatase 2A (PP2A) in mice. The results show that MARCKS, CaMKII, and the use of lung tissue do not appear to warrant further study for the determination of PMI in humans. In skeletal muscle, CnA underwent a rapid temperature-dependent cleavage (60 --> 57 kDa) over the first 48 h of postmortem interval. At 21 degrees C, this transformation was completed within 24 h. In contrast, PP2A increased within the first 24 h after which it degraded at 21 degrees C but remained stable for up to 96 h at 5 degrees C and 10 degrees C. The 60 --> 57 kDa postmortem conversion of CnA was inhibited by addition of protease inhibitors and MDL-28170 indicating a calpain pathway mediates this breakdown. Proteasome inhibition (MG-132) and calmodulin antagonism (calmidazolium) also inhibited this conversion suggesting that other protein degradation pathways also are in play. In contrast, all of the protease inhibitors and calmidazolium but not ethylene glycol tetraacetic acid led to increased levels of PP2A. The data are discussed in terms of developing a useable field-based biochemical assay for postmortem interval determination in humans and understanding the protein degradation pathways that are initiated upon death.

Differentiation inducing factor-1 (DIF-1) induces gene and protein expression of the Dictyostelium nuclear calmodulin-binding protein nucleomorphin.

The nucleomorphin gene numA1 from Dictyostelium codes for a multi-domain, calmodulin binding protein that regulates nuclear number. To gain insight into the regulation of numA, we assessed the effects of the stalk cell differentiation inducing factor-1 (DIF-1), an extracellular signalling molecule, on the expression of numA1 RNA and protein. For comparison, the extracellular signalling molecules cAMP (mediates chemotaxis, prestalk and prespore differentiation) and ammonia (NH(3)/NH(4)(+); antagonizes DIF) were also studied. Starvation, which is a signal for multicellular development, results in a greater than 80% decrease in numA1 mRNA expression within 4 h. Treatment with ammonium chloride led to a greater than 90% inhibition of numA1 RNA expression within 2 h. In contrast, the addition of DIF-1 completely blocked the decrease in numA1 gene expression caused by starvation. Treatment of vegetative cells with cAMP led to decreases in numA1 RNA expression that were equivalent to those seen with starvation. Western blotting after various morphogen treatments showed that the maintenance of vegetative levels of numA1 RNA by DIF-1 in starved cells was reflected in significantly increased numA1 protein levels. Treatment with cAMP and/or ammonia led to decreased protein expression and each of these morphogens suppressed the stimulatory effects of DIF-1. Protein expression levels of CBP4a, a calcium-dependent binding partner of numA1, were regulated in the same manner as numA1 suggesting this potential co-regulation may be related to their functional relationship. NumA1 is the first calmodulin binding protein shown to be regulated by developmental morphogens in Dictyostelium being upregulated by DIF-1 and down-regulated by cAMP and ammonia.