A Proline-Squaraine Ligand Framework (Pro-SqEB) for Stereoselective Rhodium(II)-Catalyzed Cyclopropanations.

A proline-squaraine ligand (Pro-SqEB) that demonstrates high levels of stereoselectivity in olefin cyclopropanations when anchored to a Rh2II scaffold is introduced. High yields and enantioselectivities were achieved in the cyclopropanation of alkenes with diazo compounds in the presence of Rh2(Pro-SqEB)4. Notably, the unique electronic and steric design of this catalyst enabled the use of polar solvents that are otherwise incompatible with most RhII complexes.

Inhibition of USP14 promotes TNFα-induced cell death in head and neck squamous cell carcinoma (HNSCC).

TNFα is a key mediator of immune, chemotherapy and radiotherapy-induced cytotoxicity, but several cancers, including head and neck squamous cell carcinomas (HNSCC), display resistance to TNFα due to activation of the canonical NFκB pro-survival pathway. However, direct targeting of this pathway is associated with significant toxicity; thus, it is vital to identify novel mechanism(s) contributing to NFκB activation and TNFα resistance in cancer cells. Here, we demonstrate that the expression of proteasome-associated deubiquitinase USP14 is significantly increased in HNSCC and correlates with worse progression free survival in Human Papillomavirus (HPV)- HNSCC. Inhibition or depletion of USP14 inhibited the proliferation and survival of HNSCC cells. Further, USP14 inhibition reduced both basal and TNFα-inducible NFκB activity, NFκB-dependent gene expression and the nuclear translocation of the NFκB subunit RELA. Mechanistically, USP14 bound to both RELA and IκBα and reduced IκBα K48-ubiquitination leading to the degradation of IκBα, a critical inhibitor of the canonical NFκB pathway. Furthermore, we demonstrated that b-AP15, an inhibitor of USP14 and UCHL5, sensitized HNSCC cells to TNFα-mediated cell death, as well as radiation-induced cell death in vitro. Finally, b-AP15 delayed tumor growth and enhanced survival, both as a monotherapy and in combination with radiation, in HNSCC tumor xenograft models in vivo, which could be significantly attenuated by TNFα depletion. These data offer new insights into the activation of NFκB signaling in HNSCC and demonstrate that small molecule inhibitors targeting the ubiquitin pathway warrant further investigation as a novel therapeutic avenue to sensitize these cancers to TNFα- and radiation-induced cytotoxicity.

Combined Inhibition of IAPs and WEE1 Enhances TNFα- and Radiation-Induced Cell Death in Head and Neck Squamous Carcinoma.

Head and neck squamous cell carcinoma (HNSCC) remains a prevalent diagnosis with current treatment options that include radiotherapy and immune-mediated therapies, in which tumor necrosis factor-α (TNFα) is a key mediator of cytotoxicity. However, HNSCC and other cancers often display TNFα resistance due to activation of the canonical IKK-NFκB/RELA pathway, which is activated by, and induces expression of, cellular inhibitors of apoptosis proteins (cIAPs). Our previous studies have demonstrated that the IAP inhibitor birinapant sensitized HNSCC to TNFα-dependent cell death in vitro and radiotherapy in vivo. Furthermore, we recently demonstrated that the inhibition of the G2/M checkpoint kinase WEE1 also sensitized HNSCC cells to TNFα-dependent cell death, due to the inhibition of the pro-survival IKK-NFκB/RELA complex. Given these observations, we hypothesized that dual-antagonist therapy targeting both IAP and WEE1 proteins may have the potential to synergistically sensitize HNSCC to TNFα-dependent cell death. Using the IAP inhibitor birinapant and the WEE1 inhibitor AZD1775, we show that combination treatment reduced cell viability, proliferation and survival when compared with individual treatment. Furthermore, combination treatment enhanced the sensitivity of HNSCC cells to TNFα-induced cytotoxicity via the induction of apoptosis and DNA damage. Additionally, birinapant and AZD1775 combination treatment decreased cell proliferation and survival in combination with radiotherapy, a critical source of TNFα. These results support further investigation of IAP and WEE1 inhibitor combinations in preclinical and clinical studies in HNSCC.

Lip Squamous Cell Carcinoma With Spontaneous Eruption and Drainage.

A 69-year-old woman with a newly diagnosed squamous cell carcinoma of the lower lip mucosa presented 3 days after initiating neoadjuvant immune checkpoint blockade immunotherapy with redness and swelling of the tumor site. What is your diagnosis?

Defining Microbiome Readiness for Surgery: Dietary Prehabilitation and Stool Biomarkers as Predictive Tools to Improve Outcome.

OBJECTIVES: Determine whether preoperative dietary prehabilitation with a low-fat, high-fiber diet reverses the impact of Western diet (WD) on the intestinal microbiota and improves postoperative survival. BACKGROUND: We have previously demonstrated that WD fed mice subjected to an otherwise recoverable surgical injury (30% hepatectomy), antibiotics, and a short period of starvation demonstrate reduced survival (29%) compared to mice fed a low-fat, high-fiber standard chow (SD) (100%). METHODS: Mice were subjected to 6 weeks of a WD and underwent dietary pre-habilitation (3 days vs 7 days) with a SD prior to exposure to antibiotics, starvation, and surgery. 16S rRNA gene sequencing was utilized to determine microbiota composition. Mass spectrometry measured short chain fatty acids and functional prediction from 16S gene amplicons were utilized to determine microbiota function. RESULTS: As early as 24 hours, dietary prehabilitation of WD mice resulted in restoration of bacterial composition of the stool microbiota, transitioning from Firmicutes dominant to Bacteroidetes dominant. However, during this early pre-habilitation (ie, 3 days), stool butyrate per microbial biomass remained low and postoperative mortality remained unchanged from WD. Microbiota function demonstrated reduced butyrate contributing taxa as potentially responsible for failed recovery. In contrast, after 7 days of prehabilitation (7DP), there was greater restoration of butyrate producing taxa and survival after surgery improved (29% vs 79% vs 100%: WD vs 7DP vs SD, P < 0.001). CONCLUSIONS: The deleterious effects of WD on the gut microbiota can be restored after 7 days of dietary prehabilitation. Moreover, stool markers may define the readiness of the microbiome to withstand the process of surgery including exposure to antibiotics and short periods of starvation.

Re-examining chemically defined liquid diets through the lens of the microbiome.

Trends in nutritional science are rapidly shifting as information regarding the value of eating unprocessed foods and its salutary effect on the human microbiome emerge. Unravelling the evolution and ecology by which humans have harboured a microbiome that participates in every facet of health and disease is daunting. Most strikingly, the host habitat has sought out naturally occurring foodstuff that can fulfil its own metabolic needs and also the needs of its microbiota, each of which remain inexorably connected to one another. With the introduction of modern medicine and complexities of critical care, came the assumption that the best way to feed a critically ill patient is by delivering fibre-free chemically defined sterile liquid foods (that is, total enteral nutrition). In this Perspective, we uncover the potential flaws in this assumption and discuss how emerging technology in microbiome sciences might inform the best method of feeding malnourished and critically ill patients.

Ureteroneocystostomy without ureteral remodeling for grade III-V vesicoureteral reflux treatment.

BACKGROUND: Ureteral remodeling (tapering or tailoring) is often performed alongside ureteroneocystostomy (ureteric reimplantation) procedures despite limited evidence on its role in promoting reflux resolution. OBJECTIVES: To investigate the efficacy of ureteroneocystostomy in the absence of adjuvant ureteral remodeling for promoting reflux resolution in grade III-V vesicoureteral reflux. STUDY DESIGN: A retrospective analysis identified pediatric patients who underwent open or robotic assisted ureteroneocystostomy (OUN and RAUN, respectively) without ureteral remodeling (tailoring or tapering) at a single tertiary care center. The primary endpoint of reflux resolution was defined as no reflux on latest follow up postoperative voiding cystourethrogram (VCUG). Ureteral dilation was analyzed using the ureteral diameter ratio (UDR), which normalized for image characteristics. Inclusion criteria was as follows: grade III-V reflux, accessible postoperative VCUG scan, RAUN after June 2013 following technique optimization, and no other structural urologic abnormality or associated neurogenic bladder. RESULTS: A total of 68 ureters were analyzed (Grade III = 28, Grade IV = 27, Grade V = 13, OUN = 23, RAUN = 45). Complete reflux resolution was achieved postoperatively in 96% (27/28) of grade III, 100% (27/27) of grade IV and 100% (13/13) grade V cases, for a combined resolution rate of 99%. In the one failed case, the preoperative UDR was in the second quartile and postoperatively, reflux diminished from grade III to grade I. Notably, no cases with UDRs in the largest quartile required tapering/tailoring for complete reflux resolution. DISCUSSION: Ureteral tapering and tailoring were unnecessary to achieve reflux resolution in grade III-V VUR by both OUN and RAUN. Additionally, the unsuccessful case was classified as grade III with a UDR value in the second quartile, suggesting that high grade reflux (IV-V) can be repaired without tapering with equal success rates to that of grade III VUR repair, which is classically not tapered. Tapering was unnecessary for complete reflux resolution in the cases with the largest ureteral diameter ratios (UDR). These findings are limited by the single center retrospective nature of the study. CONCLUSIONS: This study demonstrates that vesicoureteral reimplantation for resolution of grade III-V reflux is successful in the absence of ureteral remodeling techniques.

Comparative Outcomes of Double-J and Cutaneous Pyeloureteral Stents in Pediatric Robot-Assisted Laparoscopic Pyeloplasty.

Background: Comparative outcome studies investigating internal Double-J (DJ) and externalized stents have primarily been performed for open and laparoscopic pyeloplasty, with a paucity of literature surrounding outcomes in robot-assisted laparoscopic pyeloplasty (RALP). Furthermore, outcomes of a modified external stent inserted into the renal pelvis, termed cutaneous pyeloureteral (CPU) stent, remain unexamined. This study investigates outcomes of DJ and CPU stents as methods of trans-anastomotic drainage. Materials and Methods: A retrospective analysis identified pediatric patients who underwent RALP between December 2007 and January 2020 at a single tertiary center, where CPU stents were introduced in June 2012. Operative success was defined as improved or stable hydronephrosis without subsequent redo pyeloplasty. Secondary outcomes included stent reinsertion, anesthesia requirements, opioid administration, urinary tract infection (UTI), and bladder spasms. Results: A total of 103 pediatric RALP procedures were analyzed (DJ = 70, CPU = 33). Operative success (DJ = 95.7%, CPU = 100%, p = 0.55), Society for Fetal Urology (SFU) grade improvement, and length of stay were comparable. Accidental stent expulsion was only seen with CPU stents (9%; p = 0.03). Intracorporeal stent migration also occurred more frequently in CPU stents (DJ = 3%, CPU = 15%, p = 0.03). Stent reinsertion, when needed, used a DJ stent with rates of 4% and 9% for DJ and CPU stents, respectively (p = 0.38). DJ stents were removed at a later postoperative day (DJ = 45.2 ± 25.0, CPU = 8.3 ± 4.2; p < 0.001) with increased general anesthesia (DJ = 99%, CPU = 3%; p < 0.001) and intravenous (IV) opioid (DJ = 27%, CPU = 9%; p = 0.04) requirements. Finally, DJ stents had nonsignificant increased rates of UTI (DJ = 17%, CPU = 3%, p = 0.06) and bladder spasms necessitating postoperative medication (DJ = 26%, CPU = 9%, p = 0.07). Conclusions: DJ and CPU stents display equivalent success rates in pediatric RALP and similar stent reinsertion rates. Appreciable differences can inform stent selection, including higher general anesthesia requirements and IV opioid administration among DJ stents and a higher incidence of accidental stent expulsion among CPU stents. In addition, DJ stents were associated with nonsignificant increased rates of UTI and bladder spasm necessitating medication.

Harnessing the Microbiome to Optimize Surgical Outcomes in the COVID-19 Era.

In this era of testing uncertainties, changing guidelines, and incomplete knowledge, "clearing" patients for surgery in the time of SARS-COVID-19 has been met with various challenges. Efforts to increase patient fitness have long been at the forefront of surgical practicing guidelines, but the current climate requires a renewed sense of focus on these measures. It is essential to understand how dietary history, previous antibiotic exposure, and baseline microbiota can inform and optimize preoperative and postoperative management of the surgical patient in the time of COVID-19. This piece focuses on the clinical, molecular, and physiologic dynamics that occur in preparing patients for surgery during COVID-19, considering the physiologic stress inherent in the procedure itself and the importance of specialized perioperative management approaches. COVID-19 has created a renewed sense of urgency to maintain our discipline in implementing those practices that have long been confirmed to be beneficial to patient outcome. This practice, along with a renewed interest in understanding how the gut microbiome is affected by the confinement, social distancing, etc., due to the COVID pandemic, is ever more important. Therefore, here we discuss the microbiome's role as a defense against viral infection and its potential for reactivation during the process of surgery as the next frontier for surgical advancement.

GAD1 Upregulation Programs Aggressive Features of Cancer Cell Metabolism in the Brain Metastatic Microenvironment.

The impact of altered amino acid metabolism on cancer progression is not fully understood. We hypothesized that a metabolic transcriptome shift during metastatic evolution is crucial for brain metastasis. Here, we report a powerful impact in this setting caused by epigenetic upregulation of glutamate decarboxylase 1 (GAD1), a regulator of the GABA neurotransmitter metabolic pathway. In cell-based culture and brain metastasis models, we found that downregulation of the DNA methyltransferase DNMT1 induced by the brain microenvironment-derived clusterin resulted in decreased GAD1 promoter methylation and subsequent upregulation of GAD1 expression in brain metastatic tumor cells. In a system to dynamically visualize cellular metabolic responses mediated by GAD1, we monitored the cytosolic NADH:NAD+ equilibrium in tumor cells. Reducing GAD1 in metastatic cells by primary glia cell coculture abolished the capacity of metastatic cells to utilize extracellular glutamine, leading to cytosolic accumulation of NADH and increased oxidative status. Similarly, genetic or pharmacologic disruption of the GABA metabolic pathway decreased the incidence of brain metastasis in vivo Taken together, our results show how epigenetic changes in GAD1 expression alter local glutamate metabolism in the brain metastatic microenvironment, contributing to a metabolic adaption that facilitates metastasis outgrowth in that setting. Cancer Res; 77(11); 2844-56. ©2017 AACR.

Rearrangement of an Intermediate Cyclopropyl Ketene in a RhII-Catalyzed Formal [4 + 1]-Cycloaddition Employing Vinyl Ketenes as 1,4-Dipoles and Donor-Acceptor Metallocarbenes.

A RhII-catalyzed formal [4 + 1]-cycloaddition approach toward spirooxindole cyclopentenones is described. The diastereoselective cyclopropanation of vinyl ketenes with diazooxindoles as C1 synthons initiated a relatively mild formal [1,3]-migration of an intermediate cyclopropyl ketene to provide spirooxindoles in good to excellent yields (36-99%).