Gut microbiome modulates response to anti-PD-1 immunotherapy in melanoma patients.

Preclinical mouse models suggest that the gut microbiome modulates tumor response to checkpoint blockade immunotherapy; however, this has not been well-characterized in human cancer patients. Here we examined the oral and gut microbiome of melanoma patients undergoing anti-programmed cell death 1 protein (PD-1) immunotherapy (n = 112). Significant differences were observed in the diversity and composition of the patient gut microbiome of responders versus nonresponders. Analysis of patient fecal microbiome samples (n = 43, 30 responders, 13 nonresponders) showed significantly higher alpha diversity (P < 0.01) and relative abundance of bacteria of the Ruminococcaceae family (P < 0.01) in responding patients. Metagenomic studies revealed functional differences in gut bacteria in responders, including enrichment of anabolic pathways. Immune profiling suggested enhanced systemic and antitumor immunity in responding patients with a favorable gut microbiome as well as in germ-free mice receiving fecal transplants from responding patients. Together, these data have important implications for the treatment of melanoma patients with immune checkpoint inhibitors.

p53 mutations cooperate with oncogenic Kras to promote adenocarcinoma from pancreatic ductal cells.

Pancreatic cancer is one of the most lethal malignancies, with virtually all patients eventually succumbing to their disease. Mutations in p53 have been documented in >50% of pancreatic cancers. Owing to the high incidence of p53 mutations in PanIN 3 lesions and pancreatic tumors, we interrogated the comparative ability of adult pancreatic acinar and ductal cells to respond to oncogenic Kras and mutant Tp53(R172H) using Hnf1b:CreER(T2) and Mist1:CreER(T2) mice. These studies involved co-activation of a membrane-tethered GFP lineage label, allowing for direct visualization and isolation of cells undergoing Kras and mutant p53 activation. Kras activation in Mist1(+) adult acinar cells resulted in brisk PanIN formation, whereas no evidence of pancreatic neoplasia was observed for up to 6 months following Kras activation in Hnf1beta(+) adult ductal cells. In contrast to the lack of response to oncogenic Kras alone, simultaneous activation of Kras and mutant p53 in adult ductal epithelium generated invasive PDAC in 75% of mice as early as 2.5 months after tamoxifen administration. These data demonstrate that pancreatic ductal cells, whereas exhibiting relative resistance to oncogenic Kras alone, can serve as an effective cell of origin for pancreatic ductal adenocarcinoma in the setting of gain-of-function mutations in p53.

Emerging strategies for cancer immunoprevention.

The crucial role of the immune system in the formation and progression of tumors has been widely accepted. On one hand, the surveillance role of the immune system plays an important role in endogenous tumor prevention, but on the other hand, in some special circumstances such as in chronic inflammation, the immune system can actually contribute to the formation and progression of tumors. In recent years, there has been an explosion of novel targeted immunotherapies for advanced cancers. In the present manuscript, we explore known and potential various types of cancer prevention strategies and focus on nonvaccine-based cancer preventive strategies targeting the immune system at the early stages of tumorigenesis.

Mass spectrometry based method to increase throughput for kinome analyses using ATP probes.

Protein kinases play critical roles in many biological and pathological processes, making them important targets for therapeutic drugs. Here, we desired to increase the throughput for kinome-wide profiling. A new workflow coupling ActivX ATP probe (AAP) affinity reagents with isotopic labeling to quantify the relative levels and modification states of kinases in cell lysates is described. We compared the new workflow to a classical proteomics approach in which fractionation was used to identify low-abundance kinases. We find that AAPs enriched approximately 90 kinases in a single analysis involving six cell lines or states in a single run, an 8-fold improvement in throughput relative to the classical approach. In general, AAPs cross-linked to both the active and inactive states of kinases but performing phosphopeptide enrichment made it possible to measure the phospho sites of regulatory residues lying in the kinase activation loops, providing information on activation state. When we compared the kinome across the six cell lines, representative of different breast cancer clinical subtypes, we observed that many kinases, particularly receptor tyrosine kinases, varied widely in abundance, perhaps explaining the differential sensitivities to kinase inhibitor drugs. The improved kinome profiling methods described here represent an effective means to perform systematic analysis of kinases involved in cell signaling and oncogenic transformation and for analyzing the effect of different inhibitory drugs.

Is cystic fibrosis a TH17 disease?

Cystic Fibrosis (CF) is the most common lethal genetic disease in the Caucasian population and typically results in the development of bronchial inflammation, bronchiectasis, the progressive loss of lung function and ultimately death. Recently it has been shown that products of the Th(17) subset of T-cells, specifically, IL-17A and IL-17F are elevated in the sputum of CF patients. This review will go over experimental evidence supporting a role for the IL- 23/IL-17 axis in CF lung inflammation.

Developmental expression of major myelin protein genes in the CNS of X-linked hypomyelinating mutant rumpshaker.

Rumpshaker (rsh) is an X-linked mutation causing hypomyelination of the CNS of mice and has recently been identified as an allele of jimpy (jp). The mutation (known as jprsh) differs in several respects from other X-linked myelin mutants, including jp, in that mice have normal longevity, oligodendrocyte numbers are not decreased, and cell death is not a feature. Myelin sheaths are deficient in immunostainable PLP protein. The present study examines the developmental expression of the major myelin protein genes and translatability of PLP and MBP mRNA. Differences between the spinal cord and brain of mutants are evident in that mRNA levels are more markedly decreased in the brain. Protein levels are severely reduced in both locations and to a proportionately greater extent than the mRNA, particularly in the spinal cord where PLP RNA and protein are approximately 80% and 10-20%, respectively, of age-matched wild type mice. DM-20 protein, the other major product of the PLP gene, is disproportionately expressed in rumpshaker as is a 10 kDa proteolipid. In vitro translation studies indicate a marked decrease in PLP translation products from mutant RNA. There is no deficiency in the number of PLP mRNA-expressing oligodendrocytes although the abundance per cell is reduced. The data suggest that the phenotypic effects of the mutation may be associated with reduced translation of major myelin proteins, in particular PLP and its incorporation into compact myelin. However, the mutation is compatible with survival of oligodendrocytes and their differentiation to the stage of expressing PLP/DM-20 mRNA.

Mathematic model for the population biology of rabies in raccoons in the mid-Atlantic states.

A series of coupled differential equations was used to model the temporal dynamics of rabies in raccoons in the mid-Atlantic region of the United States. The model takes explicit account of the development of natural immunity to rabies and was used to evaluate culling and vaccination elimination strategies. For habitats typical of the mid-Atlantic states, and given the assumptions of the model, it was estimated that elimination of rabies in raccoons by culling may involve the annual removal of over 32% of the raccoon population or the yearly vaccination of up to 99% of the susceptible fraction. Assuming a constant marginal cost for both culling and vaccination, the model suggests that, whatever the actual cost of each method, the cheapest strategy will always involve either culling or vaccination alone. A combined strategy of culling and vaccination will be cheaper than culling alone only when the per capita cost of vaccination is around one-fifth or less the per capita cost of culling.

The fate of patients with intermittent claudication managed nonoperatively.

Of 100 patients with intermittent claudication, followed an average of six years, a surprising 78 per cent either showed improvement or remained stable regarding the presenting complaint. However, 39 per cent showed evidence of further progression of atherosclerosis. In patients with femoropopliteal occlusion in one leg, almost 40 per cent had occlusion in the one leg, almost 40 per cent had occlusion in the other leg after two to six years. The amputation rate was 7 per cent but six of these seven patients had severe diabetes. This study suggests that we are not causing limb loss by adhering to stringent criteria for bypass grafting. It also suggests that the patient with intermittent claudication without associated grave signs has a better than 50 per cent chance of improving and a better than 60 per cent chance that his disease will not show evidence of significant progression during a five to six year period. Such data should be taken into consideration when patients are considered for arterial reconstruction.

Predictability of surgical response in renovascular hypertension.

One hundred sixteen patients underwent operation for renovascular hypertension from 1962 through 1975; 64% had aortorenal reconstruction and 36% had nephrectomy. Sixty-six percent were cured and 19% were improved. Rapid sequence intravenous pyelography, radioisotope renography, and renal arteriography were equal in ability to detect renovascular hypertension. Bilateral renal biopsy specimens had excellent prognostic value when performed in a graded semiquantitative manner. Plasma renin activity was the most consistently useful criterion for prediction of surgical cure if the following requirements were used: (1) elevated peripheral plasma renin activity, (2) elevated renin from the affected kidney, and (3) suppressed renin secretion from the contralateral kidney. An angiotensin II antagonist, saralasin acetate, used in six patients before operation in an attempt to identify those whose hypertension depended on angiotensin II activity, produced a depressor response correlating well with the surgical result.

Factors influencing patency of femoropopliteal artery bypass grafts.

An analysis of 276 femoropopliteal bypass procedures performed in 264 patients at the Columbia-Presbyterian Medical Center over the past two decades showed a direct relationship of graft patency to preoperative popliteal artery runoff. Fuctional results were better than patency results. Sympathectomy and anticoagulation did not improve graft patency. The risk of amputation is outweighed by the benefits of restoration of blood flow to the ischemic extremity by a byass procedure.