Sarcoma Viral Oncogene Homolog B1 Research Articles

Structure-Based De Novo Design for the Discovery of Miniprotein Inhibitors Targeting Oncogenic Mutant BRAF.

Being a component of the Ras/Raf/MEK/ERK signaling pathway crucial for cellular responses, the VRAF murine sarcoma viral oncogene homologue B1 (BRAF) kinase has emerged as a promising target for anticancer drug discovery due to oncogenic mutations that lead to pathway hyperactivation. Despite the discovery of several small-molecule BRAF kinase inhibitors targeting oncogenic mutants, their clinical utility has been limited by challenges such as off-target effects and suboptimal pharmacological properties. This study focuses on identifying miniprotein inhibitors for the oncogenic V600E mutant BRAF, leveraging their potential as versatile drug candidates. Using a structure-based de novo design approach based on binding affinity to V600E mutant BRAF and hydration energy, 39 candidate miniprotein inhibitors comprising three helices and 69 amino acids were generated from the substructure of the endogenous ligand protein (14-3-3). Through in vitro binding and kinase inhibition assays, two miniproteins (63 and 76) were discovered as novel inhibitors of V600E mutant BRAF with low-micromolar activity, with miniprotein 76 demonstrating a specific impediment to MEK1 phosphorylation in mammalian cells. These findings highlight miniprotein 76 as a potential lead compound for developing new cancer therapeutics, and the structural features contributing to its biochemical potency against V600E mutant BRAF are discussed in detail.

Genomic medicine advances for brain tumors.

Cancer genome profiling has revealed important genetic alterations that serve as prognostic indicators and guides for treatment decisions, enabling precision medicine. The shift to molecular diagnosis of brain tumors, as reflected in the 2021 World Health Organization Classification of Tumors of the Central Nervous System, is a crucial role for treatment decision-making. This review discusses the significance and role of cancer genome profiling in precision medicine for malignant brain tumors, particularly gliomas. Furthermore, we explore the progress in cancer genome analysis, focusing on cancer gene panel testing, integration of genomic information in brain tumor classification, and hereditary tumors. Additionally, we discuss the transformative effect of genomic medicine on early detection, risk assessment, and precision medicine strategies. The tumor mutational burden in brain tumors is considered low, but the application of molecular targeted drugs, such as isocitrate dehydrogenase inhibitors, v-raf murine sarcoma viral oncogene homolog B1 inhibitors, fibroblast growth factor receptor inhibitors, neurotrophic tyrosine receptor kinase, mechanistic target of rapamycin inhibitors, and anti-programmed death receptor-1 antibody drugs are promising for glioma treatment. We also discuss the future prospects of molecular targeted drugs.

Temporal trends and regional variability in BRAF and KRAS genetic testing in Denmark (2010-2022): Implications for precision medicine.

This study aims to evaluate the developments in the testing of Kirsten Rat Sarcoma viral oncogene homolog (KRAS) and v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) mutations across different cancer types and regions in Denmark from 2010 to 2022. Using comprehensive data from the Danish health registries, we linked molecular test results from the Danish Pathology Registry with cancer diagnoses from the Danish National Patient Registry between 2010 and 2022. We assessed the frequency and distribution of KRAS and BRAF mutations across all cancer types, years of testing, and the five Danish regions. The study included records of KRAS testing for 30 671 patients and BRAF testing for 30 860 patients. Most KRAS testing was performed in colorectal (78%) and lung cancer (18%), and BRAF testing in malignant melanoma (13%), colorectal cancer (67%), and lung cancer (12%). Testing rates and documentation mutational subtypes increased over time. Reporting of wildtype results varied between lung and colorectal cancer, with underreporting in lung cancer. Regional variations in testing and reporting were observed. Our study highlights substantial progress in KRAS and BRAF testing in Denmark from 2010 to 2022, evidenced by increased and more specific reporting of mutational test results, thereby improving the precision of cancer diagnosis and treatment. However, persistent regional variations and limited testing for cancer types beyond melanoma, colorectal, and lung cancer highlight the necessity for a nationwide assessment of the optimal testing approach.

BRAF V600E Mutation in Malignant Melanoma-A Romanian Research Experience.

Background and Objectives: The most common mutation in malignant melanoma (MM) is the single-point mutation of v-raf murine sarcoma viral oncogene homolog B1 (BRAF) oncogene. Our study aims to evaluate BRAF V600E mutation, highlighting its frequency differences in primary versus metastatic MM. Materials and Methods: The study group comprised 133 patients diagnosed with MM in several county hospitals of the north-eastern region of Romania who have been assigned for investigation into BRAF V600E mutation in the private medical system. The material consisted of archived formalin-fixed paraffin-embedded (FFPE) blocks. BRAF V600E mutation was identified using the fully automated IdyllaTM BRAF mutation test system. Results: Out of the total of 133 cases, 78 cases were primary tumors, while 55 cases were metastatic MMs. Genetic analysis revealed the presence of BRAF V600E mutation in 66 cases (49.62%) and the wild-type genotype in 67 cases (50.37%). We found a statistically significant difference of the mutation frequency according to age (p = 0.0072). The mutated genotype was found in 45 cases out of 78 primary MMs (57.69%) and in 21 cases out of 55 secondary MMs (38.18%), with a statistically significant difference in favor of primary tumors (p = 0.0413). The correlations between the histopathological types, Clark's level, Breslow index, ulceration, and lymphovascular invasion, respectively, and the mutated genotype were not statistically significant. BRAF V600E mutation was identified in 15 out of 40 secondary tumors with lymph node location (37.5%) and in 6 out of 15 secondary tumors with another location (40%) without statistically significant differences between the mutation frequency and the location of the secondary tumors. Conclusions: Our results support MM high genetic heterogeneity, pointing out the relationship between BRAF V600E mutation and several clinicopathological characteristics, in primary and metastatic MMs, stressing the importance of BRAF testing implementation in Romania.

Is there a prognostic difference among stage I lung adenocarcinoma patients with different BRAF-mutation status?

The data of the prognostic role of V-Raf murine sarcoma viral oncogene homolog B1 (BRAF) mutations in early-stage lung adenocarcinoma (LUAD) patients is scarce. This study aimed to investigate the proportion, clinicopathological features, and prognostic significance of patients with stage I LUAD carrying BRAF mutations. We collected 431 patients with pathological stage I LUAD from cBioPortal for Cancer Genomics and 1604 LUAD patients tested for BRAF V600E and epidermal growth factor receptor (EGFR) mutations from Shanghai Pulmonary Hospital. Survival curves were drawn by the Kaplan-Meier method and compared by log-rank test. Cox proportional hazard models, propensity-score matching (PSM), and overlap weighting (OW) were performed in this study. The primary endpoint was recurrence-free survival (RFS). The proportion of BRAF mutations was estimated at 5.6% in a Caucasian cohort. BRAF V600E mutations were detected in six (1.4%) patients in Caucasian populations and 16 (1.0%) patients in Chinese populations. Two BRAF V600E-mutant patients were detected to have concurrent EGFR mutations, one for 19-del and one for L858R. For pathological stage I LUAD patients, BRAF mutations were not significantly associated with worse RFS than wild-type BRAF patients (HR = 1.111; p = 0.885). After PSM and OW, similar results were presented (HR = 1.352; p = 0.742 and HR = 1.246; p = 0.764, respectively). BRAF V600E mutation status also lacked predictive significance for RFS (HR, 1.844; p = 0.226; HR = 1.144; p = 0.831 and HR = 1.466; p = 0.450, respectively). In this study, we demonstrated that BRAF status may not be capable of predicting prognosis in stage I LUAD patients. There is a need for more data to validate our findings.

Repurposing Metabolic Inhibitors in the Treatment of Colon Adenocarcinoma Patient-Derived Models.

The effect of agonists on AMP-activated protein kinase (AMPK), mainly metformin and phenformin, has been appreciated in the treatment of multiple types of tumors. Specifically, the antitumor activity of phenformin has been demonstrated in melanomas containing the v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) activating mutation. In this report, we elucidated the synergistic antitumor effects of biguanides with metabolism inhibitors on colon tumors. Phenformin with 2-deoxy-D-glucose (2DG) inhibited tumor cell growth in cancer cell lines, including HT29 cells harboring BRAF- and p53-mutations. Biochemical analyses showed that two chemotherapeutics exerted cooperative effects to reduce tumor growth through cell cycle arrest, apoptosis, and autophagy. The drugs demonstrated activity against phosphorylated ERK and the gain-of-function p53 mutant protein. To demonstrate tumor regressive effects in vivo, we established patient-derived models, including xenograft (PDX) and organoids (PDO). Co-treatment of biguanides with chemotherapeutics efficiently reduced the growth of patient-derived colon models in comparison to treatment with a single agent. These results strongly suggest that significant therapeutic advantages would be achieved by combining AMPK activators such as phenformin and cancer metabolic inhibitors such as 2DG.

The Impact of BRAF Mutation Status on Survival Outcomes and Treatment Patterns among Metastatic Colorectal Cancer Patients in Alberta, Canada.

Colorectal cancer presents via multiple different clinical phenotypes that can arise from a variety of different genetic and molecular alterations. The aim of this study was to describe survival outcomes and treatment patterns of metastatic colorectal cancer (mCRC) patients by v-raf murine sarcoma viral oncogene homolog B1 (BRAF) mutation status. The Alberta Cancer Registry was used to identify all patients >18 years old who had been diagnosed with mCRC in Alberta between 1 January 2017 and 31 December 2019 and had received at least one cycle of systemic therapy. Treatment patterns were compared between wild-type and mutant BRAF mCRC patients. Cox regression models and Kaplan-Meier curves were created to assess survival differences by both treatment pattern and BRAF status. A total of 488 patients were identified with mCRC, of which 42 (11.4%) were confirmed to have a BRAF mutation. The most common first-line treatment regimen was either capecitabine and oxaliplatin (CAPOX) or leucovorin calcium (folinic acid), fluorouracil, and oxaliplatin (FOLFOX). The median overall survival for mCRC patients was 20.01 months. Mutant BRAF patients had a median survival of 8.21 months compared to 20.03 months among those with wild-type BRAF. BRAF mutations among mCRC patients are associated with a considerably poor prognosis, reinforcing the need for clinical BRAF testing among newly diagnosed patients to better understand their prognosis.

Abstract C153: Rare BRAF mutations in menlanoma and beyond: Rationalizing the afficacy of B-raf inhibitors via HPC-based in silico/in vitro investigations

Abstract Melanoma is a highly aggressive type of cancer that affects the integumentary system and for which a family history of the disease, a fair complexion, the presence of a large number of moles, and skin exposure to natural/artificial ultraviolet (UV) radiation constitute established risk factors for malignancy development. The v-RAF murine sarcoma viral oncogene homolog B1 (BRAF) is a serine/threonine protein kinase that plays a critical role in the RAS-RAF-MEK-ERK mitogen–activated protein kinase (MAPK) cell signaling pathway. Despite over 20 years of research into the regulation and function of the RAF proteins, it was only relatively recently that the BRAF isoform is mutated at a high frequency in different human cancers, identifying this kinase as another important oncogene along this pathway. FFocusing on melanoma, activating BRAF mutations were identified in 37%−53% of patients with the malignant form of this pathology, the most prevalent, missense kinase alteration being the replacement of the small, apolar residue valine (V) with the negatively-charged, phosphorylation mimicking glutamic acid (E) at position 600 (BRAFV600E) within the protein catalytic (i.e., ATP binding) site. It is interesting to note that BRAFV600E is not a UV-driven mutation; in fact, it may also be found in the molecular profile of atypical benign nevi; moreover, although BRAFV600E is the most frequent mutation (accounting for nearly 40% of all melanomas and in approximately 90% of BRAF-mutant melanomas), other more or less frequent activating variants in BRAF have also been reported, which include other aminoacidic substitutions at the same position (e.g., V600K/D/R), G469A/V/S, L597Q/R/S/V, A598V, and K601E/N/T, among others. Importantly, these mutations are also found in other cancers, e.g., thyroid cancer, colorectal cancer, and some brain malignancies including glioblastoma, pilocytic astrocytoma, and pediatric low-grade glioma. In this multidisciplinary work, we focused on some of these rare BRAF variants and studied their ability to interact with several, first-line FDA approved BRAF initbitors (BRAFis) from a structural, chemico-phisical and in vitro perspectives. To the purpose, we employed a combitation of in silico techniques, based on the use of high-performance computing (HPC), chemico-physical and spectroscopical techniques, and in vitro tests to verify the interactions between these mutated BRAF isoforms with the inhibitors. As a main point, we were able to determine the binding thermodinamics and kinetics of the selected BRAFis to the mutant BRAF proteins, and each BRAF/drug complex was characterized from a structural standpoint. All these information ultimately revelaed that some of the BRAF isoforms are able to effectively bind the corresponding BRAi, with consequent switch-off of the signaling patwhay, at least in vitro. The presented mutlidisciplinary protocol could be adoped in the future to predict the response of newly discovered BARF variants and/or variants of unknown significance towards current or newly-designed BRAFis. Citation Format: Sabrina Pricl, Erik Laurini, Domenico Marson, Gabriele Cavalieri. Rare BRAF mutations in menlanoma and beyond: Rationalizing the afficacy of B-raf inhibitors via HPC-based in silico/in vitro investigations [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C153.

FGFR blockade inhibits targeted therapy-tolerant persister in basal FGFR1- and FGF2-high cancers with driver oncogenes

Cancer cell resistance arises when tyrosine kinase inhibitor (TKI)-targeted therapies induce a drug-tolerant persister (DTP) state with growth via genetic aberrations, making DTP cells potential therapeutic targets. We screened an anti-cancer compound library and identified fibroblast growth factor receptor 1 (FGFR1) promoting alectinib-induced anaplastic lymphoma kinase (ALK) fusion-positive DTP cell’s survival. FGFR1 signaling promoted DTP cell survival generated from basal FGFR1- and fibroblast growth factor 2 (FGF2)-high protein expressing cells, following alectinib treatment, which is blocked by FGFR inhibition. The hazard ratio for progression-free survival of ALK-TKIs increased in patients with ALK fusion-positive non-small cell lung cancer with FGFR1- and FGF2-high mRNA expression at baseline. The combination of FGFR and targeted TKIs enhanced cell growth inhibition and apoptosis induction in basal FGFR1- and FGF2-high protein expressing cells with ALK-rearranged and epidermal growth factor receptor (EGFR)-mutated NSCLC, human epidermal growth factor receptor 2 (HER2)-amplified breast cancer, or v-raf murine sarcoma viral oncogene homolog B1 (BRAF)-mutated melanoma by preventing compensatory extracellular signal-regulated kinase (ERK) reactivation. These results suggest that a targeted TKI-induced DTP state results from an oncogenic switch from activated oncogenic driver signaling to the FGFR1 pathway in basal FGFR1- and FGF2-high expressing cancers and initial dual blockade of FGFR and driver oncogenes based on FGFR1 and FGF2 expression levels at baseline is a potent treatment strategy to prevent acquired drug resistance to targeted TKIs through DTP cells regardless of types of driver oncogenes.

Clinicopathological relevance of BRAF and SMO mutations in Chinese patients with ameloblastoma

Ameloblastomas are benign tumors associated with recurrence and morbidity. Mutations in the V-Raf murine sarcoma viral oncogene homolog B1 (BRAF) and smoothened (SMO) genes have been identified in ameloblastomas. The mutation rate of BRAF in different regions and mutation sites of SMO remains controversial. This study assesses the relationship between these mutations and clinicopathological features of ameloblastoma in Chinese patients. Ameloblastomas were surgically removed from 30 patients and BRAF gene polymorphisms were detected using DNA sequencing analysis. We also examined the relationship between BRAF or SMO mutations and clinicopathological parameters. BRAF V600E mutation was detected in 18 of 30 ameloblastomas. No significant correlation was found between BRAF V600E mutation and age, sex, location, histologic type, capsular invasion, or tumor recurrence. Five cases carried an SMO T364N mutation in exon 5, whereas six carried an SMO S590 T mutation in exon 10. The SMO mutation rate in patients aged ≤ 20 years was significantly higher than that in patients aged > 20 years. SMO T364N and S590 T mutations were closely related to age and capsular invasion. These findings indicate that BRAF V600E, SMO T364N, and SMO S590 T mutations play important roles in the pathogenesis of ameloblastoma. Key highlights The BRAF V600E mutation was highly prevalent in Chinese patients with ameloblastoma. SMO T364N and S590 T mutations are closely related to age and capsular invasion. The BRAF V600E, SMO T364N, and SMO S590 T mutations play important roles in the pathogenesis of ameloblastoma.

Oncologic relevance of genetic alterations in sporadic synchronous and solitary colorectal cancer: a retrospective multicenter study

BackgroundOncologic impact of genetic alteration across synchronous colorectal cancer (CRC) still remains unclear. This study aimed to compare the oncologic relevance according to genetic alteration between synchronous and solitary CRC with performing systematic review.MethodsMulticenter retrospective analysis was performed for CRC patients with curative resection. Genetic profiling was consisted of microsatellite instability (MSI) testing, RAS (K-ras, and N-ras), and BRAF (v-Raf murine sarcoma viral oncogene homolog B1) V600E mutation. Multivariate analyses were conducted using logistic regression for synchronicity, and Cox proportional hazard model with stage-adjusting for overall survival (OS) and disease-free survival (DFS).ResultsIt was identified synchronous (n = 36) and solitary (n = 579) CRC with similar base line characteristics. RAS mutation was associated to synchronous CRC with no relations of MSI and BRAF. During median follow up of 77.8 month, Kaplan–meier curves showed significant differences according to MSI-high for OS, and in RAS, and BRAF mutation for DFS, respectively. In multivariable analyses, RAS and BRAF mutation were independent factors (RAS, HR = 1.808, 95% CI = 1.18–2.77, p = 0.007; BRAF, HR = 2.417, 95% CI = 1.32–4.41, p = 0.004). Old age was independent factor for OS (HR = 3.626, 95% CI = 1.09–12.00, p = 0.035).ConclusionThis study showed that oncologic outcomes might differ according to mutation burden characterized by RAS, BRAF, and MSI between synchronous CRC and solitary CRC. In addition, our systematic review highlighted a lack of data and much heterogeneity in genetic characteristics and survival outcomes of synchronous CRC relative to that of solitary CRC.

BRAF Mutation Heterogeneity Detected Using Circulating Tumor DNA Sequencing in Synchronous Colon Cancer: A Case Report.

Synchronous colorectal cancer, which occurs in approximately 4.8-8.4% of all colorectal cancers, has a genetic profile with a higher rate of v-raf murine sarcoma viral oncogene homolog B1 (BRAF) mutation and microsatellite instability-high than solitary colorectal cancer. However, little information is available on heterogeneity among tumor lesions because of difficulty in performing genetic tests in all lesions in clinical practice. A 44-year-old man presented with multiple recurrent lung metastases 42 months after the endoscopic resection of early stage synchronous ascending and sigmoid colon cancers. The genetic testing of sigmoid colon cancer tissue samples, their state being more advanced than that of ascending colon cancer, revealed a v-Ki-ras 2 Kirsten rat sarcoma viral oncogene homolog mutation (G13C) and BRAF wild type. However, the tumor was refractory to initial chemotherapy and rapidly progressed to new liver metastases. Therefore, we suspected that there may be biological heterogeneity between the primary sigmoid colon lesion and liver metastases. Next, we performed next-generation sequencing on circulating tumor DNA from the patient's plasma (Foundation One Liquid CDx®), which revealed the V600E mutation of BRAF, suggesting that there was genetic heterogeneity among the synchronized primary lesions, one of which was responsible for the chemo-refractory rapid-growing liver metastases. Genetic profiling with liquid biopsy at the time of recurrence and metastasis may be useful in patients with multiple synchronous cancers because there is less heterogeneity between primary and metastatic sites.

Anticancer effects of Mori radicis cortex, Mori ramulus, Angelica tenuissima, and Inonotus obliquus extract mixtures on B16F10 mur ine melanoma cells via up regulation of p53 and down regulation of Akt expression

Purpose: To investigate the anticancer effects of the extract mixture of Mori radicis cortex, Mori ramulus, Angelica tenuissima, and Inonotus obliquus extract (MRME), a new herbal preparation from Korea, on B16F10 cells.
 Methods: The MRME was extracted with water. Cell Counting Kit-8 (CCK-8) assays and 4′,6- diamidino-2-phenylindole (DAPI) staining were used to investigate the effect of MRME on cell proliferation and apoptosis in vitro. The expression of p53, p-p53, and phosphorylated Akt (p-Akt) were analyzed by western blotting. Wound-healing assay was used to analyze cell migration.
 Results: Based on CCK-8 and DAPI staining results, MRME inhibited the growth of B16F10 cells and induced apoptosis in B16F10 cells in a time- and dose-dependent manner (p < 0.05). MRME increased the expression of p53 and p-p53 and decreased the expression of p-Akt in a dose-dependent manner. MRME treatment inhibited cell migration and invasion (p < 0.05).
 Conclusion: Mori Radicis Cortex Mixture Extract exerts anticancer effect by inducing the expression of p53 and p-p53 and decreasing the expression of p-Akt, which may benefit patients with malignant melanoma when used in combination with v-raf murine sarcoma viral oncogene homolog B1 (BRAF) inhibitors.

Clinicopathological Profile of a Cohort of Patients With Malignant Melanoma in the United Kingdom.

Introduction Malignant melanoma (MM) is potentially a fatal type of skin cancer and a major health concern for the Caucasian population. It is a heterogeneous disease with a wide spectrum of manifestations. Therefore, in this study, we evaluated the clinicopathological characteristics of MM. Methods We retrospectively studied the clinicopathological characteristics of MM in 167 biopsy-proven cases of MM reported between January 2020 and December 2021 at Kings Mill Hospital, Sutton-in-Ashfield, United Kingdom. Clinical data such as the age, sex, and anatomical site of the lesion were obtained from the clinical referral forms. Biopsies of the lesions were performed, and the specimens collected were sent to the laboratory for histopathological study and v-raf murine sarcoma viral oncogene homolog B1 (BRAF) mutation evaluation. Formalin-fixed paraffin-embedded blocks (FFPE) were prepared, sectioned, and stained with hematoxylin and eosin for histological examination. Results A total of 167 cases of MM were included in the study. The age range was 23-96 years, with the median age at diagnosis found to be 66 years; males were more commonly affected (52.1%). The median Breslow thickness was 1.20 mm. The median mitotic activity was 1.0/mm2. The lower limb was the most common site of involvement (27.5%), followed by the thorax (25.1%). The most common histological subtype was superficial spreading melanoma (SSM) (77.8%), followed by nodular melanoma (14.4%). The in situ component was present in 95.8% of cases; a majority (92.2%) of the cases showed vertical growth phase, 71.9% of cases were at Clark's level IV of invasion, regression was noted in 70.7% of cases, ulceration was present in 21.6% of cases, and microsatellites were present in 3% of cases. Perineural invasion was present in 3% of cases, and lymphovascular invasion (LVI) was present in 4.2% of cases. BRAF mutation testing was performed on 36 cases, out of which 20 cases (55.6%) showed BRAF mutation. Acral lentiginous melanoma and nodular melanoma were most likely to show ulceration (66.7% and 37.5%, respectively). SSM and lentigo maligna melanoma were more likely to be associated with regression. Conclusion The study demonstrated that MM is prevalent among the elderly population with male predominance; SSM was found to be the most common subtype. The study further demonstrated various clinicopathological features of MM and its association with histological subtypes.

Discovery of a highly potent pan-RAF inhibitor IHMT-RAF-128 for cancer treatment

Although rat sarcoma viral oncogene homolog (RAS) mutations occur in about 30% of solid tumors, targeting RAS mutations other than KRAS-G12C is still challenging. As an alternative approach, developing inhibitors targeting RAF, the downstream effector of RAS signaling, is currently one of the main strategies for cancer therapy. Selective v-raf murine sarcoma viral oncogene homolog B1 (BRAF)-V600E inhibitors Vemurafenib, Encorafenib, and Dabrafenib have been approved by FDA and received remarkable clinical responses, but these drugs are ineffective against RAS mutant tumors due to limited inhibition on dimerized RAF. In this study, we developed a highly potent pan-RAF inhibitor, IHMT-RAF-128, which exhibited similarly high efficacies in inhibiting both partners of the RAF dimer, and showed potent anti-tumor efficacy against a variety of cancer cells harboring either RAF or RAS mutations, especially Adagrasib and Sotorasib (AMG510) resistant-KRAS-G12C secondary mutations, such as KRAS-G12C–Y96C and KRAS-G12C–H95Q. In addition, IHMT-RAF-128 showed excellent pharmacokinetic profile (PK), and the bioavailability in mice and rats were 63.9%, and 144.1%, respectively. Furthermore, IHMT-RAF-128 exhibited potent anti-tumor efficacy on xenograft mouse tumor models in a dose-dependent manner without any obvious toxicities. Together, these results support further investigation of IHMT-RAF-128 as a potential clinical drug candidate for the treatment of cancer patients with RAF or RAS mutations.

Prognostic value of von Willebrand factor levels in patients with metastatic melanoma treated by immune checkpoint inhibitors

BackgroundAn increased incidence of thrombotic complications associated with an increased mortality rate has been observed under immune checkpoint inhibition (ICI). Recent investigations on the coagulation pathways have highlighted the direct...

Imaging Mass Spectrometry for the Classification of Melanoma Based on BRAF/NRAS Mutational Status

Mutations of the oncogenes v-raf murine sarcoma viral oncogene homolog B1 (BRAF) and neuroblastoma RAS viral oncogene homolog (NRAS) are the most frequent genetic alterations in melanoma and are mutually exclusive. BRAF V600 mutations are predictive for response to the two BRAF inhibitors vemurafenib and dabrafenib and the mitogen-activated protein kinase kinase (MEK) inhibitor trametinib. However, inter- and intra-tumoral heterogeneity and the development of acquired resistance to BRAF inhibitors have important clinical implications. Here, we investigated and compared the molecular profile of BRAF and NRAS mutated and wildtype melanoma patients' tissue samples using imaging mass spectrometry-based proteomic technology, to identify specific molecular signatures associated with the respective tumors. SCiLSLab and R-statistical software were used to classify peptide profiles using linear discriminant analysis and support vector machine models optimized with two internal cross-validation methods (leave-one-out, k-fold). Classification models showed molecular differences between BRAF and NRAS mutated melanoma, and identification of both was possible with an accuracy of 87-89% and 76-79%, depending on the respective classification method applied. In addition, differential expression of some predictive proteins, such as histones or glyceraldehyde-3-phosphate-dehydrogenase, correlated with BRAF or NRAS mutation status. Overall, these findings provide a new molecular method to classify melanoma patients carrying BRAF and NRAS mutations and help provide a broader view of the molecular characteristics of these patients that may help understand the signaling pathways and interactions involving the altered genes.

Survival comparison of first-line treatment regimens in patients with braf-mutated advanced colorectal cancer: a multicenter retrospective study

BackgroundPatients with V-Raf murine sarcoma viral oncogene homolog B1 (BRAF) V600E-mutated advanced colorectal cancer (CRC) have a poor prognosis, and treatment options that can improve outcome are still under investigation. The purpose of this study was to discuss the differences of overall survival (OS) and progression-free survival (PFS) between patients with BRAF V600E-mutated advanced CRC who were treated with chemotherapy alone and chemotherapy combined with targeted therapy in advanced first-line therapy.MethodsGrouping of 61 patients according to first-line treatment regimen (chemotherapy alone/chemotherapy combined with bevacizumab). Kaplan–Meier method and log-rank test were used to compare OS and PFS. Cox proportional hazards regression model was used to measure the risk of first-line medication therapies while correcting for confounding factors that may affect PFS and OS.ResultsThere was no significant difference in OS between patients treated with chemotherapy alone and those treated with chemotherapy combined with bevacizumab (P = 0.93; HR, 1.027; 95% CI, 0.555–1.901). Likewise, there was no significant difference in PFS between the two groups (P = 0.29; HR, 0.734; 95% CI, 0.413–1.304). Subgroup analysis showed that OS and PFS of different treatment regimens were not significantly different among subgroups. Multivariate analysis suggested that surgical treatment of primary tumor (P = 0.001; HR, 0.326; 95% CI, 0.169–0.631) and presence of liver metastasis (P = 0.009; HR, 2.399; 95% CI, 1.242–4.635) may serve as independent prognostic indicators in patients with BRAF-mutated advanced CRC. Surgical treatment of the primary tumor (P = 0.041; HR, 0.523; 95% CI, 0.280–0.974) was significantly associated with PFS too.ConclusionFor patients with BRAF V600E-mutated advanced CRC, chemotherapy alone did not differ significantly in OS and PFS compared with chemotherapy + bevacizumab for advanced first-line therapy. Chemotherapy combined with targeted therapy did not render a survival benefit to these patients, demonstrating that the importance of developing new treatment options for this population.

RIDR-PI-103, ROS-activated prodrug PI3K inhibitor inhibits cell growth and impairs the PI3K/Akt pathway in BRAF and MEK inhibitor-resistant BRAF-mutant melanoma cells.

Reactive oxygen species (ROS) levels are elevated after acquisition of resistance to v-raf murine sarcoma viral oncogene homolog B1 (BRAF) inhibitors including dabrafenib and MEK inhibitors such as trametinib in BRAF-mutant melanoma. To circumvent toxicity to PI-103 (a pan PI3K inhibitor), we utilized a novel ROS-induced drug release (RIDR)-PI-103, with a self-cyclizing moiety linked to PI-103. Under high ROS conditions, RIDR-PI-103 releases PI-103, which inhibits conversion of phosphatidylinositol 4,5-bisphosphate (PIP 2 ) to phosphatidylinositol 3,4,5-triphosphate (PIP 3 ). Previous findings demonstrate that trametinib and dabrafenib-resistant (TDR) cells maintain p-Akt levels compared to parental counterparts and have significantly higher ROS. This is a rationale to explore the efficacy RIDR-PI-103 in TDR cells. We tested the effect of RIDR-PI-103 on melanocytes and TDR cells. RIDR-PI-103 exhibited less toxicity compared to PI-103 at 5 µM in melanocytes. RIDR-PI-103 significantly inhibited TDR cell proliferation at 5 and 10 µM. Twenty-four hour treatment with RIDR-PI-103 inhibited p-Akt, p-S6 (Ser240/244) and p-S6 (Ser235/236). We assessed the mechanism of activation of RIDR-PI-103, using glutathione or t-butyl hydrogen peroxide (TBHP) on the TDR cells in the presence or absence of RIDR-PI-103. Addition of the ROS scavenger glutathione to RIDR-PI-103 significantly rescued the cell proliferation in TDR cell lines while addition of the ROS inducer TBHP and RIDR-PI-103 inhibited cell proliferation in WM115 and WM983B TDR cell lines. Examining the efficacy of RIDR-PI-103 on BRAF and MEK inhibitor-resistant cells will expand possible treatment options and open avenues for the development of new ROS-based treatment therapies for BRAF-mutant melanoma patients.

Recent Developments and Challenges in Molecular-Targeted Therapy of Non-Small-Cell Lung Cancer

Treatment of lung cancer with conventional therapies, which include radiation, surgery, and chemotherapy results in multiple undesirable adverse or side effects. The major clinical challenge in developing new drug therapies for lung cancer is resistance, which involves mutations and disturbance in various signaling pathways. Molecular abnormalities related to epidermal growth factor receptor (EGFR), v-Raf murine sarcoma viral oncogene homolog B1 (B-RAF) Kirsten rat sarcoma virus (KRAS) mutations, translocation of the anaplastic lymphoma kinase (ALK) gene, mesenchymal-epithelial transition factor (MET) amplification have been studied to overcome the resistance and to develop new therapies for non-small cell lung cancer (NSCLC). But, inevitable development of resistance presents limits the clinical benefits of various new drugs. Here, we review current progress in the development of molecularly targeted therapies, concerning six clinical biomarkers: EGFR, ALK, MET, ROS-1, KRAS, and B-RAF for NSCLC treatment.