Viewing the immune checkpoint VISTA: landscape and outcomes across cancers.

BACKGROUND: Optimizing immune checkpoint inhibitor (ICI) therapy may require identification of co-targetable checkpoint pathways via immune profiling. Herein, we analyzed the transcriptomic expression and clinical correlates of V-domain immunoglobulin suppressor of T-cell activation (VISTA), a promising targetable checkpoint. PATIENTS AND METHODS: RNA sequencing was carried out on 514 tissues reflecting diverse advanced/metastatic cancers. Expression of eight immune checkpoint markers [lymphocyte-activation gene 3 (LAG-3), tumor necrosis factor receptor superfamily 14 (TNFRSF14), programmed cell death protein 1 (PD-1), programmed death-ligand 1 (PD-L1), programmed death-ligand 2 (PD-L2), B- and T-lymphocyte attenuator (BTLA), T-cell immunoglobulin and mucin domain-containing protein 3 (TIM-3), cytotoxic T-lymphocyte antigen 4 (CTLA-4)], in addition to VISTA, was analyzed, along with clinical outcomes. RESULTS: High VISTA RNA expression was observed in 32% of tumors (66/514) and was the most common highly expressed checkpoint among the nine assessed. High VISTA expression was independently correlated with high BTLA, TIM-3, and TNFRSF14, and with a diagnosis of pancreatic, small intestine, and stomach cancer. VISTA transcript levels did not correlate with overall survival (OS) from metastatic/advanced disease in the pan-cancer cohort or with immunotherapy outcome (progression-free survival and OS from the start of ICI) in 217 ICI-treated patients. However, in ICI-treated pancreatic cancer patients (n = 16), median OS was significantly shorter (from immunotherapy initiation) for the high- versus not-high-VISTA groups (0.28 versus 1.21 years) (P = 0.047); in contrast, VISTA levels were not correlated with OS in 36 pancreatic cancer patients who did not receive ICI. CONCLUSION: High VISTA expression correlates with high BTLA, TIM-3, and TNFRSF14 checkpoint-related molecules and with poorer post-immunotherapy survival in pancreatic cancer, consistent with prior literature indicating that VISTA is prominently expressed on CD68+ macrophages in pancreatic cancers and requiring validation in larger prospective studies. Immunomic analysis may be important for individualized precision immunotherapy.

Targeting the FGF/FGFR axis and its co-alteration allies.

BACKGROUND: We analyzed the FGF/FGFR and co-alteration cancer landscape, hypothesizing that combination therapy might be useful in the presence of co-drivers. MATERIALS AND METHODS: We describe FGF/FGFR-altered pathways, prognosis, and co-alterations [cBioPortal (N = 7574)] and therapeutic outcomes [University of California San Diego Molecular Tumor Board (MTB) (N = 16)]. RESULTS: Patients whose cancers harbored FGF/FGFR alterations (N = 1074) versus those without them (N = 6500) had shorter overall survival (OS) (median: 23.1 versus 26.4 months, P = 0.038) (cBioPortal). Only 6.1% (65/1074 patients) had no pathogenic co-alterations accompanying FGF/FGFR axis abnormalities. The most frequently co-altered pathways/genes involved: TP53 (70%); cell cycle (58%); PI3K (55%); and receptor tyrosine kinases and mitogen-activated protein kinase (MAPK) (65%). Harboring alterations in both FGF/FGFR and in the TP53 pathway or in the cell cycle pathway correlated with shorter OS (versus FGF/FGFR-altered without those co-altered signals) (P = 0.0001 and 0.0065). Four of 16 fibroblast growth factor receptor (FGFR) inhibitor-treated patients presented at MTB attained durable partial responses (PRs) (9, 12, 22+, and 52+ months); an additional two, stable disease (SD) of ≥6 months (13+ and 15 months) [clinical benefit rate (SD ≥ 6 months/PR) = 38%]. Importantly, six patients with cyclin pathway co-alterations received the CDK4/6 inhibitor palbociclib (75 mg p.o. 3 weeks on, 1 week off) and the multikinase FGFR inhibitor lenvatinib (10 mg p.o. daily); three (50%) achieved a PR [9 (ovarian), 12 (biliary), and 52+ months (osteosarcoma)]. Palbociclib and lenvatinib were tolerated well. CONCLUSIONS: FGF/FGFR alterations portend a poor prognosis and are frequently accompanied by pathogenic co-aberrations. Malignancies harboring co-alterations that activate both cyclin and FGFR pathways can be co-targeted by CDK4/6 and FGFR inhibitors.

Using machine learning to construct nomograms for patients with metastatic colon cancer.

AIM: Patients with synchronous colon cancer metastases have highly variable overall survival (OS), making accurate predictive models challenging to build. We aim to use machine learning to more accurately predict OS in these patients and to present this predictive model in the form of nomograms for patients and clinicians. METHODS: Using the National Cancer Database (2010-2014), we identified right colon (RC) and left colon (LC) cancer patients with synchronous metastases. Each primary site was split into training and testing datasets. Nomograms predicting 3- year OS were created for each site using Cox proportional hazard regression with lasso regression. Each model was evaluated by both calibration (comparison of predicted vs observed OS) and validation (degree of concordance as measured by the c-index) methodologies. RESULTS: A total of 11 018 RC and 8346 LC patients were used to construct and validate the nomograms. After stratifying each model into five risk groups, the predicted OS was within the 95% CI of the observed OS in four out of five risk groups for both the RC and LC models. Externally validated c-indexes at 3 years for the RC and LC models were 0.794 and 0.761, respectively. CONCLUSIONS: Utilization of machine learning can result in more accurate predictive models for patients with metastatic colon cancer. Nomograms built from these models can assist clinicians and patients in the shared decision-making process of their cancer care.

Advanced basal cell cancer: concise review of molecular characteristics and novel targeted and immune therapeutics.

Metastatic basal cell carcinoma is an ultra-rare manifestation of a common disease, appearing in 0.0028%-0.5% of basal cell carcinomas. Initial therapeutic efforts focused on cytotoxic chemotherapy administration. However, it is now known that the Hedgehog signaling pathway is crucial for basal cell proliferation and Hedgehog pathway mutations may lead to tumorigenesis; thus, small-molecule inhibitors of alterations in the components of this pathway, including smoothened (SMO) and GLI, have been the focus of recent therapeutic developments. Indeed, the European Medicines Agency and the Food and Drug Administration have approved the SMO inhibitors, vismodegib and sonidegib, with additional GLI inhibitors currently in clinical trials. Molecular profiling of these tumors has revealed other potential targets for therapy, including high tumor mutational burden and PD-L1 amplification, which predict response to immune checkpoint blockade (PD-1 and PD-L1 inhibitors). An illustrative patient with a giant, advanced, unresectable basal cell carcinoma who obtained an ongoing complete remission after treatment with a combination of an immune checkpoint inhibitor (due to the tumor's high mutational burden) and the Hedgehog inhibitor vismodegib is described. A fuller understanding of the genomic portfolio of these patients can assist in developing novel, rational therapeutic approaches that should continue to improve responses and outcomes.

Carotid endarterectomy with normal findings from a completion study: Is there need for early duplex scan?

OBJECTIVE: The objective of this study was to determine the value of early (< 6 months) duplex scanning after carotid endarterectomy (CEA) with an intraoperative completion study with normal results. Attention was paid to restenosis rates and reoperation for recurrent stenosis within the first 6 months. METHODS: A retrospective review was performed on 380 CEAs (338 patients) with intraoperative completion studies and duplex surveillance within the first 6 months. Results of completion studies, restenosis rates, and recurrent symptoms were evaluated for each operation. Studies were performed from 0 to 200 days postoperatively (median, 28). RESULTS: Intraoperative completion studies included 333 angiograms, 26 duplex scans, and 21 angiograms with duplex scans. Of the 380 intraoperative completion studies, 28 (7.5%) had abnormal findings, including 14 abnormal internal carotid arteries (ICAs). Twenty-four procedures were revised, and the findings of all repeat completion studies were normal. Of the initial completion studies, in four cases, abnormalities (3 ICAs) were insignificant and did not warrant further intervention. Follow-up ICA duplex scans had normal results after 364 (95.8%) CEAs. There were 14 mild recurrent ICA stenoses and two moderate recurrent ICA stenoses; neither had abnormal findings from the completion study. There were no severe recurrent ICA stenoses. External carotid artery (ECA) recurrent stenosis included 7 mild, 15 moderate, and 9 severe restenoses. CONCLUSIONS: Only 0.5% of CEAs developed moderate restenosis. No procedures had severe recurrent stenosis on duplex scan within the first 6 months, and none required intervention. Duplex surveillance in the first 6 months is relatively unproductive, providing that there were normal results from an intraoperative completion study for each patient. Routine surveillance can be started at 1 year.

Protein kinase C activation downregulates the expression and function of the basolateral Na+/K+/2Cl(-) cotransporter.

The basolateral Na+/K+/2Cl(-) cotransporter (NKCC1) has been shown to be an independent regulatory site for electrogenic Cl(-) secretion. The proinflammatory phorbol ester, phorbol 12-myristate 13-acetate (PMA), which activates protein kinase C (PKC), inhibits basal and cyclic adenosine monophosphate (cAMP)-stimulated NKCC1 activity in T84 intestinal epithelial cells and decreases the steady state levels of NKCC1 mRNA in a time- and dose-dependent manner. The levels of NKCC1 protein also fall in accordance with the NKCC1 mRNA transcript and these levels are unaffected by 4alpha-phorbol, which does not activate PKC. Inhibition of maximal (cAMP-stimulated) NKCC1 functional activity by PMA was first detected by 1 h, whereas decreases in the steady state levels of NKCC1 mRNA were not detectable until 4 h. NKCC1 mRNA expression recovers toward control levels with extended treatment of cells with PMA suggesting that the PMA effects on NKCC1 expression are mediated through activation of PKC. Although NKCC1 mRNA and protein levels return to control values after extended PMA exposure, NKCC1 functional activity does not recover. Immunofluorescence imaging suggest that the absence of functional recovery is due to failure of newly synthesized NKKC1 protein to reach the cell surface. We conclude that NKCC1 has the capacity to be regulated at the level of de novo expression by PKC, although decreased NKCC1 expression alone cannot account for either early or late loss of NKCC1 function.

Effects of bryostatin 1, a novel anticancer agent, on intestinal transport and barrier function: role of protein kinase C.

BACKGROUND: Bryostatin 1 is a novel chemotherapeutic agent that activates specific members of the protein kinase C (PKC) family in a complex pattern overlapping with, but distinct from, that of tumor-promoting phorbol esters. Phorbol esters profoundly altered epithelial phenotype, abolishing both barrier function and Cl secretion (the latter due to loss of a key transport site, the Na-K-Cl cotransporter). The effects of bryostatin 1 on these parameters are unknown. METHODS: Cl secretion and barrier function of T84 human intestinal epithelia were assessed as cyclic adenosine monophosphate-stimulated short-circuit current and transepithelial resistance, respectively. Na-K-Cl cotransporter function and mRNA expression were assayed by 86Rb uptake and Northern analysis. RESULTS: Bryostatin 1 reduced Cl secretion, Na-K-Cl cotransport, and cotransporter mRNA expression. Unlike phorbol esters, these effects were largely transient. In contrast to phorbol esters, bryostatin 1 did not decrease barrier function. CONCLUSIONS: Bryostatin 1 transiently inhibits Na-K-Cl cotransport and Cl secretion, possibly through a PKC isoform also targeted by phorbol esters. Unlike phorbol esters, bryostatin 1 does not impair barrier function. The data imply that bryostatin 1 and phorbol esters differentially affect a PKC isoform involved in junctional regulation, and that epithelial transport and barrier function may be regulated by distinct PKC isoforms.

Osmotic regulation of intestinal epithelial Na(+)-K(+)-Cl- cotransport: role of Cl- and F-actin.

Previous data indicate that adenosine 3',5'-cyclic monophosphate activates the epithelial basolateral Na(+)-K(+)-Cl- cotransporter in microfilament-dependent fashion in part by direct action but also in response to apical Cl- loss (due to cell shrinkage or decreased intracellular Cl-). To further address the actin dependence of Na(+)-K(+)-Cl- cotransport, human epithelial T84 monolayers were exposed to anisotonicity, and isotopic flux analysis was performed. Na(+)-K(+)-Cl- cotransport was activated by hypertonicity induced by added mannitol but not added NaCl. Cotransport was also markedly activated by hypotonic stress, a response that appeared to be due in part to reduction of extracellular Cl- concentration and also to activation of K+ and Cl- efflux pathways. Stabilization of actin with phalloidin blunted cotransporter activation by hypotonicity and abolished hypotonic activation of K+ and Cl- efflux. However, phalloidin did not prevent activation of cotransport by hypertonicity or isosmotic reduction of extracellular Cl-. Conversely, hypertonic but not hypotonic activation was attenuated by the microfilament disassembler cytochalasin D. The results emphasize the complex interrelationship among intracellular Cl- activity, cell volume, and the actin cytoskeleton in the regulation of epithelial Cl- transport.