Improved production of class I phosphatidylinositol 4,5-bisphosphate 3-kinase.

Phosphatidylinositol 4,5-bisphosphate 3-kinases (PI3K) are a family of kinases whose activity affects pathways needed for basic cell functions. As a result, PI3K is one of the most mutated genes in all human cancers and serves as an ideal therapeutic target for cancer treatment. Expanding on work done by other groups we improved protein yield to produce stable and pure protein using a variety of modifications including improved solubility tag, novel expression modalities, and optimized purification protocol and buffer. By these means, we achieved a 40-fold increase in yield for p110α/p85α and a 3-fold increase in p110α. We also used these protocols to produce comparable constructs of the ß and δ isoforms of PI3K. Increased yield enhanced the efficiency of our downstream high throughput drug discovery efforts on the PIK3 family of kinases.

Two hearts beat as one: the debate over RAS dimers continues.

A recent report by Yun et al. describes the detection of RAS dimers using intact mass spectrometry and investigates the role that membrane lipids, nucleotide state, and binding partners have in their formation.

Successful cetuximab rechallenge in metastatic colorectal cancer: A case report.

BACKGROUND: Metastatic colorectal cancer (mCRC) treatment has been evolving and increasingly driven by tumor biology and gene expression analysis. Rechallenge with epidermal growth factor receptor (EGFR) inhibitors (anti-EGFR) represents a promising strategy for patients with RAS wild-type (RAS-wt) mCRC and circulating tumor DNA has emerged as a potential selection strategy. Herein, we report the case of a RAS-wt mCRC patient who had a successful response to cetuximab rechallenge. CASE SUMMARY: Our patient was diagnosed with stage IV RAS-wt, microsatellite-stable rectosigmoid junction adenocarcinoma. He was started on first-line treatment with FOLFIRI and cetuximab and achieved partial response, allowing for a left hepatectomy (R0), followed by post-operative chemotherapy and an anterior resection; progression-free survival (PFS) of 16 months was obtained. Due to hepatic and nodal relapse, second-line treatment with FOLFOX and bevacizumab was started with partial response; metastasectomy was performed (R0), achieving a PFS of 11 months. After a 15 months anti-EGFR-free interval, FOLFIRI and cetuximab were reintroduced upon disease progression, again with partial response and a PFS of 16 months. Following extensive hepatic relapse, cetuximab was reintroduced and a marked clinical and analytical improvement was seen, after only one cycle. RAS-wt status was confirmed on circulating tumor DNA. The patient's overall survival exceeded 5 years. CONCLUSION: Our case provides real-world data to support cetuximab rechallenge in later lines of RAS-wt mCRC treatment.

Investigation and Characterization of the RAS/RAF/MEK/ERK Pathway and Other Signaling Pathways in Chronic Sinusitis with Nasal Polyps.

BACKGROUND: The clinical outcomes of drug treatments and surgical interventions for chronic sinusitis with nasal polyps (CRSwNPs) are suboptimal, and the high recurrence rate remains a significant challenge in clinical practice. Targeted therapies such as biologics provide new perspectives and directions for treating CRSwNP. SUMMARY: With the continuous investigation of signaling pathways, RAS/RAF/MEK/ERK signaling pathway and other signaling pathways including Hippo, JAK-STAT, Wnt, TGF-ß, PI3K, Notch, and NF-κB were confirmed to play an important role in the progression of CRSwNP. Among them, the abnormality of RAS/RAF/MEK/ERK signaling pathway is accompanied by the abnormality of this apoptotic component, which may provide new research directions for targeting the components of signaling pathways to mediate apoptosis. KEY MESSAGES: Abnormalities in signaling pathways are particularly important in studying the pathogenesis and treatment of CRSwNP. Therefore, this review summarizes the ongoing investigation and characterization of RAS/RAF/MEK/ERK signaling pathway and other signaling pathways in CRSwNP, which provides constructive ideas and directions for improving the treatment of CRSwNP.

A review and perspective paper: Ras oncogene gets modest, from kingpin to mere henchman.

The concomitant activation of both the YAP1 co-transcription factor and RAS GTPases is a hallmark of several aggressive cancers, though the intricacies of their relationship and implications for oncogenesis are still poorly understood. This review has presented a cooperative model where YAP1 and RAS are not independently acting oncogenes but rather interdependently acting ones, with each fulfilling an essential role within the oncogenic process. YAP1 is responsible for initiating the expression of key proteins that contribute to various cancer traits. However, these proteins must often be transported into the cytoplasm to exert their effects. We suggest that oncogenic RAS actually facilitates this transport, enabling the phosphorylation and subsequent activation of the nuclear transporter XPO1 (aka Exportin1). This mechanism is particularly crucial for anti-apoptotic proteins. Instead of being sequestered within the nucleus in an ineffective state, these proteins are rather shuttled into the cytoplasm. Within the cytoplasm, they can effectively inhibit apoptosis, undermining by these means the efficacy of chemotherapeutic agents designed to induce cell death in cancer cells. Therefore, a clearer understanding of the oncogenic partnership between RAS and YAP1 will likely provide new insights into the molecular underpinnings of cancer and highlight as well potential targets for therapeutic interventions designed to disrupt this pernicious interaction.

Mediating kinase activity in Ras-mutant cancer: potential for an individualised approach?

It is widely acknowledged that there is a considerable number of oncogenic mutations within the Ras superfamily of small GTPases which are the driving force behind a multitude of cancers. Ras proteins mediate a plethora of kinase pathways, including the MAPK, PI3K, and Ral pathways. Since Ras was considered undruggable until recently, pharmacological targeting of pathways downstream of Ras has been attempted to varying success, though drug resistance has often proven an issue. Nuances between kinase pathway activation in the presence of various Ras mutants are thought to contribute to the resistance, however, the reasoning behind activation of different pathways in different Ras mutational contexts is yet to be fully elucidated. Indeed, such disparities often depend on cancer type and disease progression. However, we are in a revolutionary age of Ras mutant targeted therapy, with direct-targeting KRAS-G12C inhibitors revolutionising the field and achieving FDA-approval in recent years. However, these are only beneficial in a subset of patients. Approximately 90% of Ras-mutant cancers are not KRAS-G12C mutant, and therefore raises the question as to whether other distinct amino acid substitutions within Ras may one day be targetable in a similar manner, and indeed whether better understanding of the downstream pathways these various mutants activate could further improve therapy. Here, we discuss the favouring of kinase pathways across an array of Ras-mutant oncogenic contexts and assess recent advances in pharmacological targeting of various Ras mutants. Ultimately, we will examine the utility of individualised pharmacological approaches to Ras-mediated cancer.

Experimental variables determine the outcome of RAS-RAS interactions.

RAS clustering at the cell membrane is critical to activate signaling in cells, but whether this clustering is mediated exclusively by its c-terminal hypervariable region, receives contributions from the G-domain of RAS, and/or is influenced by secondary effectors has been intensely debated. Reports that G-domain mutations do not modulate RAS-RAS interactions, have led some to question the validity of previous experiments that indicate the G-domain plays a role in RAS clustering/interactions. Here we reconcile these findings by clarifying the impact of experimental variables, such as protein expression levels, cellular context, RAS zygosity, and secondary effector interactions on RAS clustering. Lack of control over these variables impact the results using G-domain mutations across various assay systems and can lead to unsound conclusions.

KRAS mutations detection methodology: from RFLP to CRISPR/Cas based methods.

In personalized cancer medicine, the identification of KRAS mutations is essential for making treatment decisions and improving patient outcomes. This work presents a comprehensive review of the current approaches for detection of KRAS mutations in different cancers. We highlight the value of fast and reliable KRAS mutations discovery and the effectiveness of molecular testing for selecting individuals who might benefit from targeted therapy. We provide an overview of various methods and tools available for detecting KRAS mutations, such as digital droplet PCR, next-generation sequencing (NGS), and polymerase chain reaction (PCR). We also address the difficulties and limitations in the identification of KRAS mutations, namely tumor heterogeneity and the emergence of resistance mechanisms. This article aims to guide clinicians in KRAS mutation identification.

Unresectable Ulcerative Colitis Associated Colon Cancer in a Young Japanese Patient: A Case Report.

We herein present the case of a 30-year-old Japanese male patient with ulcerative colitis (UC) who was admitted to our hospital because of significant ascites. Upon evaluation, the patient was diagnosed with unresectable UC-associated cancer (UCAC), localized in the transverse colon. Using gene profiling of the tumor tissue, anti-epidermal growth factor receptor (EGFR) antibody combination chemotherapy was selected. Subsequently, the patient exhibited a temporary response to this regimen, with an enhancement in his quality of life and he was able to survive for 12 months. This case underscores the potential benefits of aggressive chemotherapy tailored to the gene profile in UCAC treatment, offering insights into potential avenues for improving the patient prognosis.

Impact of the local renin-angiotensin system in perivascular adipose tissue on vascular health and disease.

Perivascular adipose tissue (PVAT) is found locally around blood vessels. It has the ability to release vasoactive chemicals, such as factors that relax and contract blood vessels. PVAT is now recognized as an endocrine organ with metabolic activity and as a "protagonist" for maintaining vascular homeostasis. Angiotensin II, a powerful vasoconstrictor of the renin-angiotensin system (RAS) that can increase blood pressure and vascular tone, is produced locally by PVAT. To mitigate the multiple vascular effects of angiotensin II, PVAT also generates molecules such as angiotensin (1-7), adiponectin, and nitric oxide. Reactive oxygen species and proinflammatory cytokines are produced in greater amounts when PVAT-mediated angiotensin II is present, resulting in endothelial dysfunction, inflammation, atherosclerosis, and other vascular disorders. The anticontractile and procontractile nature of PVAT is frequently disrupted in obese individuals, which increases the production of angiotensin II and decreases the production of anti-inflammatory and vasodilatory factors. These changes in turn exacerbate vascular inflammation, hypertension, and atherosclerosis. PVAT, which is crucial for maintaining vascular homeostasis, loses its anticontractile effect in obesity due to adipocyte hypertrophy, inflammation, and oxidative stress, exacerbating endothelial dysfunction. Overactive RAS in PVAT facilitates the migration and proliferation of vascular smooth muscle cells and atherosclerotic plaques, both of which accelerate the development of atherosclerosis. Targeting PVAT and the local RAS can offer therapeutic benefits in treating hypertension, atherosclerosis, and other vascular diseases. This review highlights the scientific underpinnings of the function of PVAT in regulating the autocrine and paracrine activities of vascular RAS constituents.

Development and safety of investigational and approved drugs targeting the RAS function regulation in RAS mutant cancers.

The RAS gene family holds a central position in controlling key cellular activities such as migration, survival, metabolism, and other vital biological processes. The activation of RAS signaling cascades is instrumental in the development of various cancers. Although several RAS inhibitors have gained approval from the United States Food and Drug Administration (FDA) for their substantial antitumor effects, their widespread and severe adverse reactions significantly curtail their practical usage in the clinic. Thus, there exists a pressing need for a comprehensive understanding of these adverse events, ensuring the clinical safety of RAS inhibitors through the establishment of precise management guidelines, suitable intermittent dosing schedules, and innovative combination regimens. This review centers on the evolution of RAS inhibitors in cancer therapy, delving into the common adverse effects associated with these inhibitors, their underlying mechanisms, and the potential strategies for mitigation.

An Unexpected Finding of a PTPN11 Germline Mutation in a Patient With a Melanocytic Lesion With a Somatic MAP2K1 Mutation. Coincidence or Not?

Melanocytic tumors are a diverse group of lesions and are traditionally classified based on a combination of clinical presentation as well as histological examination. More recently, molecular diagnostics has become an increasingly important part of differentiating different melanocytic lesions in the current WHO standards. This molecular testing, however, can result in unexpected findings. In this report, we describe that molecular testing of a clinical atypical melanocytic lesion showed a mutation in the MAP2K1 gene as well as an unexpected germline mutation in PTPN11, indicative of Noonan syndrome. Based on these findings we concluded that the patient had a MAP2K1 associated melanocytic lesion with Noonan syndrome as an incidental finding. Melanomas are classically not associated with Noonan syndrome. However, we hypothesized that the germline mutations of PTPN11 and the somatic second hit mutation in the MAP2K1 genes might be involved in the formation of the aforementioned lesion. As they are both part of the RAS-MAPK pathway. Furthermore, with the expansion of molecular diagnostics in melanomas, we expect to find an increase in unexpected (germline) mutations.

First-Line Therapy in Metastatic, RAS Wild-Type, Left-Sided Colorectal Cancer: Should Everyone Receive Anti-EGFR Therapy?

PURPOSE OF REVIEW: This narrative review explores the efficacy and applicability of anti-EGFR therapy as the first-line treatment for patients with RAS wild-type (WT) left-sided metastatic colorectal cancer (mCRC). It critically examines current guidelines, along with recent evidence in the literature, to assess whether it should be universally applied. RECENT FINDINGS: Recent evidences highlight the variability of the response to anti-EGFR therapies due to molecular diversity and several clinical factors, such as RAS mutational status and primary tumor location. Anti-EGFR plus chemotherapy is the standard first-line treatment for most patients with MSS, RAS-WT, left-sided mCRC. Whether this combination is the best treatment for these patients remains an open question. This review delves into the role of EGFR inhibition in mCRC, focusing on clinical factors and the knowledge of biology, molecular targets, and biomarkers. It underscores the crucial role of a personalized approach, empowering healthcare providers and equipping them with the confidence to make informed decisions.

RAS mutant transverse colon cancer with multiple liver metastases achieving long-term disease-free survival with postoperative maintenance therapy with aflibercept + FOLFIRI and four repeated radical resections: a case report.

BACKGROUND: Management of patients with colorectal liver metastases (CRLMs) requires a multidisciplinary approach. For patients with progression of RAS mutant tumors, the choice of angiogenesis inhibitors can be controversial. Here, we report a patient with RAS mutant CRLMs achieving long-term disease-free survival with repeated R0 resections and perioperative treatment, especially aflibercept + FOLFIRI (5-fluorouracil, levofolinate, irinotecan), which may have prevented long-term recurrence. CASE PRESENTATION: The patient was a 37 year-old woman diagnosed with RAS mutant transverse colon cancer with 19 LMs. As the metastases were limited to the liver, we introduced systemic chemotherapy aiming at conversion surgery. After six cycles of bevacizumab + FOLFOXIRI (5-fluorouracil, levofolinate, oxaliplatin, irinotecan), we performed partial hepatectomy for all LMs, and left hemicolectomy for the primary tumor after another four cycles of bevacizumab + FOLFIRI. Three months after surgery, the patient presented with massive ovarian metastases with carcinomatous ascites. We conducted bilateral oophorectomy, and initiated aflibercept + FOLFIRI therapy considering the possibility of resistance to bevacizumab. The patient was recurrence-free for 2 years during aflibercept + FOLFIRI treatment. After its discontinuation, two distant metastases developed. Both were resectable and the patient achieved recurrence-free survival of 2 years and 3 months after the last operation (6 years since initiation of treatment), without additional chemotherapy. CONCLUSIONS: We believe that multidisciplinary treatment aimed at complete resection could lead to long-term survival even in patients with repeated recurrence of CRLMs. Aflibercept + FOLFIRI could be effective in controlling metastasis of RAS mutant colon cancer even after treatment with bevacizumab.

Association of various RAS codon mutations and prognostic outcomes of patients with colorectal liver metastases after hepatectomy.

PURPOSE: The prognostic and predictive value of RAS mutations in patients with colorectal liver metastases (CRLM) who have undergone hepatectomy holds substantial importance. The present study aimed to investigate the impact of different RAS codon mutations on long-term survival in CRLM patients. METHODS: A retrospective analysis was conducted on clinicopathological data from 399 CRLM patients with RAS mutations who underwent hepatectomy between January 2000 and December 2020. The RAS mutation gene status was assessed in KRAS codons (G12, G13, Q61, and A146) and NRAS codons (G12, G13, and Q61). Survival curves were generated using the Kaplan-Meier plotter and compared using the log-rank test. Univariate and multivariate analyses were performed to analyze the clinicopathological data. RESULTS: In the entire cohort, patients with KRAS G12 mutations exhibited the most favorable prognosis (p = 0.018). Comparatively, patients harboring KRAS Q61 mutations experienced poorer overall survival (OS) with a median of 15 months versus 33 months (p = 0.011) when compared to those with KRAS G12 mutations. Moreover, patients with NRAS Q61 mutations also showed decreased OS with a median of 26 months versus 33 months (p = 0.020) in comparison to KRAS G12 mutation patients. The results of multivariate analysis showed that both KRAS Q61 mutation (HR 2.130; 95% CI 1.088-4.168; p = 0.027) and NRAS Q61 mutation (HR 2.877; 95% CI 1.398-5.922; p = 0.004) were independent influencing factors of OS. Based on all identified risk factors, patients with RAS mutation were divided into high-risk and low-risk groups. Notably, in the high-risk group, the incorporation of postoperative chemotherapy was associated with longer OS, while it did not improve the survival of patients in the low-risk group. CONCLUSIONS: KRAS Q61 and NRAS Q61 mutations are promising predictors for OS in CRLM patients after hepatectomy. Postoperative chemotherapy may significantly benefit CRLM patients with RAS mutations, particularly those identified as high-risk.

Acute freshwater CO2 exposure does not impair seawater transfer in three different sizes of Atlantic salmon (Salmo salar) subjected to different photoperiod manipulations.

There is a growing interest in Atlantic salmon (Salmo salar) aquaculture to extend the time fish are reared in freshwater (FW) recirculating aquaculture systems (RAS), producing larger FW salmon that can then be induced to undergo smoltification before transfer into marine net pens for grow-out and harvest. Smolts can be produced by photoperiod (PT) manipulation in RASs, but little is known about how delaying smoltification to larger body sizes affects susceptibility to elevated CO2 levels (hypercapnia), which can occur at high stocking densities in FW RAS or during transport from FW RAS rearing facilities to marine net pens. To address this, Atlantic salmon were reared from hatch to one of three different sizes (~230, ~580, or ~1300 g) in FW (3 ppt) under continuous light (24:0, light:dark). Once fish reached the desired sizes, a group of salmon were maintained on continuous light 24L:0D to serve as a control salmon. A second group of salmon were exposed to 8 weeks of 12L:12D and then to 4 weeks of 24L:0D to serve as PT treatment salmon, which is the PT manipulation commonly used in Atlantic salmon aquaculture to induce smoltification. At the end of PT manipulation, both control and PT treatment salmon were exposed to 0% or 1.5% CO2 (30 mg/L) for 96 h in FW and then transferred to air-equilibrated seawater (SW, 35 ppt, normocapnia). Salmon were sampled at the end of the 96-h FW CO2 exposure and at 24 h and 7 days in SW for measurements of blood ion/acid-base status, muscle water content (MWC), and gill and kidney Na+/K+ ATPase (NKA) activity. Exposure to 96 h of CO2 in FW resulted in acid-base disturbances in fish from all three size classes, with decreases in blood pH and increases in blood PCO2 and plasma [HCO3 -] but no mortality. Despite these large acid-base disturbances in FW, after transfer to normocapnic SW, there were no significant effects of CO2 exposure on extracellular blood pH, intracellular red blood cell pH, or plasma osmoregulatory status for all three sizes of post-smolt salmon. In general, SW transfer was associated with significant increases in plasma ions and osmolality, as well as gill and kidney NKA activity after 24 h and 1 week in SW with no significant impacts between different sizes of salmon. Thus, exposure to 30 mg CO2/L that mimics levels experienced during transport from FW RAS to an SW transfer site may have minimal effects on Atlantic salmon smolts up to 1300 g.

Implementation of a Perioperative Lung Protective Ventilation Protocol for Robotic-Assisted Surgeries.

This project sought to educate providers on the benefits of lung protective ventilation (LPV), implement a LPV protocol in robotic surgery, and evaluate adherence to the protocol in the adult (≥ 18 years) robotic-assisted surgery population. This project used a pre/post quality improvement design with a retrospective chart review and periodic knowledge, attitude, and practice surveys over the course of 6 months. This project retrospectively reviewed electronic medical records to assess adherence to the LPV protocol. The type of surgery; ventilator settings including positive end-expiratory pressure, FiO2, tidal volume, SpO2, ventilator mode, compliance, driving pressure and peak pressure; patient height and weight; patient body mass index; and American Society of Anesthesiologists physical status classification were collected. Analyzed results compared baseline preeducation data and data collected at 3- and 6-months postimplementation. Adherence to the LPV protocol parameters of tidal volume (P < .001), respiratory rate (P = .014), and driving pressure (P < .001) within LPV limits improved with statistical significance from pre- to postimplementation. Provider confidence and knowledge increased from pre- to posteducation (P = .049). Adherence to a LPV protocol improved with education and information tools.

Outcomes of robotic surgery for inflammatory bowel disease using the Medtronic Hugo™ Robotic-Assisted Surgical platform: a single center experience.

PURPOSE: The aim of the study was to compare the perioperative outcomes of patients affected by inflammatory bowel disease (IBD) who underwent surgery performed through laparoscopy or using the Medtronic Hugo™ RAS. METHODS: This is a retrospective study from a prospectively maintained database comparing laparoscopic vs. robotic-assisted surgery for IBD from 01/11/2017 to 15/04/2024. All procedures were performed by a single surgeon robotic-naïve with a large experience in laparoscopic surgery for IBD. The robotic procedures were performed using the Medtronic Hugo™ RAS platform. Outcomes were 30-day postoperative complications, operative time, conversion rate, intraoperative complications, length of hospital stay, and readmission rate. RESULTS: Among 121 consecutive patients, 80 underwent laparoscopic (LG) and 41 robotic-assisted surgery (RG). Baseline, preoperative and disease-specific characteristics were comparable except for older age (50 [38-56] vs. 38 [28-54] years; p = 0.05) and higher albumin level (42 [40-44] vs. 40 [38-42] g/L, p = 0.006) in the RG. The intracorporeal anastomosis was more frequent in the RG (80% vs. 6%; p < 0.001) with longer operative time (240 vs. 205 min; p = 0.006), while the conversion rate was not different (5% vs. 10%, p = 0.49). Surgical procedure types were equally distributed between the two groups, and the rate of intra-abdominal septic complication (IASC) was comparable across the different procedures. Postoperative complications were similar, including the rate of IASC (5% vs. 5%, p = 1), postoperative ileus (5% vs. 7.5%, p = 0.71), bleeding (2% vs. 5%, p = 0.66), and Clavien-Dindo > 2 complications (7% vs. 6%; p = 1). CONCLUSION: IBD surgery performed using the Medtronic Hugo™ RAS is safe and feasible, with similar postoperative outcomes when compared to the laparoscopic approach.

GLP-1 receptor agonists may enhance the effects of desmopressin in individuals with AVP deficiency: a case series and proposed mechanism.

BACKGROUND: Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have diverse effects on sodium and water homeostasis. They decrease thirst perception, potentially inhibit arginine vasopressin (AVP) production, and induce natriuresis. We present three cases of AVP deficiency (AVP-D) where GLP-1 RA initiation led to desmopressin dose reduction. CASES: Three patients with AVP-D on stable desmopressin therapy started GLP-1 RAs for type 2 diabetes mellitus or obesity. Following weight loss and decreased thirst, all patients reduced their desmopressin dose while maintaining normal thirst and urine output. DISCUSSION: GLP-1 RAs influence sodium and water homeostasis through various mechanisms. In individuals with intact AVP systems, GLP-1 RAs may directly suppress AVP production and induce natriuresis in the kidney leading to increased water excretion. In AVP-D, with exogenous desmopressin replacing endogenous AVP, the osmotic permeability of collecting ducts is primarily influenced by desmopressin dose. Thus, increased distal fluid delivery may allow for lower desmopressin doses to maintain water balance. CONCLUSION: Our findings indicate a potential interaction between GLP-1 RAs and desmopressin in AVP-D. Clinicians should reassess desmopressin dosage upon initiating GLP-1 RA therapy.