A review on structure-function mechanism and signaling pathway of serine/threonine protein PIM kinases as a therapeutic target.

The proviral integration for the Moloney murine leukemia virus (PIM) kinases, belonging to serine/threonine kinase family, have been found to be overexpressed in various types of cancers, such as prostate, breast, colon, endometrial, gastric, and pancreatic cancer. The three isoforms PIM kinases i.e., PIM1, PIM2, and PIM3 share a high degree of sequence and structural similarity and phosphorylate substrates controlling tumorigenic phenotypes like proliferation and cell survival. Targeting short-lived PIM kinases presents an intriguing strategy as in vivo knock-down studies result in non-lethal phenotypes, indicating that clinical inhibition of PIM might have fewer adverse effects. The ATP binding site (hinge region) possesses distinctive attributes, which led to the development of novel small molecule scaffolds that target either one or all three PIM isoforms. Machine learning and structure-based approaches have been at the forefront of developing novel and effective chemical therapeutics against PIM in preclinical and clinical settings, and none have yet received approval for cancer treatment. The stability of PIM isoforms is maintained by PIM kinase activity, which leads to resistance against PIM inhibitors and chemotherapy; thus, to overcome such effects, PIM proteolysis targeting chimeras (PROTACs) are now being developed that specifically degrade PIM proteins. In this review, we recapitulate an overview of the oncogenic functions of PIM kinases, their structure, function, and crucial signaling network in different types of cancer, and the potential of pharmacological small-molecule inhibitors. Further, our comprehensive review also provides valuable insights for developing novel antitumor drugs that specifically target PIM kinases in the future. In conclusion, we provide insights into the benefits of degrading PIM kinases as opposed to blocking their catalytic activity to address the oncogenic potential of PIM kinases.

Unraveling the Interplay of KRAS, NRAS, BRAF, and Micro-Satellite Instability in Non-Metastatic Colon Cancer: A Systematic Review.

Microsatellite Instability (MSI-H) occurs in approximately 15% of non-metastatic colon cancers, influencing patient outcomes positively compared to microsatellite stable (MSS) cancers. This systematic review focuses on the prognostic significance of KRAS, NRAS, and BRAF mutations within MSI-H colon cancer. Through comprehensive searches in databases like MEDLINE, EMBASE, and others until 1 January 2024, we selected 8 pertinent studies from an initial pool of 1918. These studies, encompassing nine trials and five observational studies involving 13,273 patients, provided insights into disease-free survival (DFS), survival after recurrence, and overall survival. The pooled data suggest that while KRAS and BRAF mutations typically predict poorer outcomes in MSS colorectal cancer, their impact is less pronounced in MSI contexts, with implications varying across different stages of cancer and treatment responses. In particular, adverse effects of these mutations manifest significantly upon recurrence rather than affecting immediate DFS. Our findings confirm the complex interplay between genetic mutations and MSI status, emphasizing the nuanced role of MSI in modifying the prognostic implications of KRAS, NRAS, and BRAF mutations in colon cancer. This review underscores the importance of considering MSI alongside mutational status in the clinical decision-making process, aiming to tailor therapeutic strategies more effectively for colon cancer patients.

It was not possible to detect BRAF V600E mutation in circulating cell-free DNA from patients with ameloblastoma: A diagnostic accuracy study.

BACKGROUND: The objective of this study is to evaluate the diagnostic accuracy of plasma-based liquid biopsy for the detection of the BRAF V600E mutation in circulating cell-free DNA from patients with ameloblastoma. METHODS: This is a prospective diagnostic accuracy study conducted based on the Standards for Reporting Diagnostic Accuracy recommendations. The index test was the plasma-based liquid biopsy, whereas the reference standard was the conventional tissue biopsy. The target condition was the detection of BRAF V600E mutation. The study population consisted of individuals with ameloblastoma recruited from three tertiary hospitals from Brazil. A negative control group composed of three individuals with confirmed wild-type BRAF lesions were included. The participants underwent plasma circulating cell-free DNA and tumor tissue DNA isolation, and both were submitted to using competitive allele-specific TaqMan™ real-time polymerase chain reaction technology mutation detection assays. Sensitivity and specificity measures and positive and negative predictive values were calculated. RESULTS: Twelve patients with conventional ameloblastoma were included. BRAF V600E mutation was detected in 11/12 (91.66%) ameloblastoma tissue samples. However, the mutation was not detected in any of the plasma-based liquid biopsy circulating cell-free DNA samples in both ameloblastomas and negative control group. The sensitivity and specificity of plasma-based liquid biopsy for the detection of the BRAF V600E mutation in circulating cell-free DNA was 0.0 and 1.0, respectively. The agreement between index test and reference standard results was 26.66%. CONCLUSION: Plasma-based liquid biopsy does not seem to be an accurate method for the detection of the BRAF V600E mutation in circulating circulating cell-free DNA from patients with ameloblastoma, regardless of tumor size, anatomic location, recurrence status, and other clinicopathological features.

A phase 1 study of triple-targeted therapy with BRAF, MEK, and AKT inhibitors for patients with BRAF-mutated cancers.

BACKGROUND: Aberrant PI3K/AKT signaling in BRAF-mutant cancers contributes to resistance to BRAF inhibitors. The authors examined dual MAPK and PI3K pathway inhibition in patients who had BRAF-mutated solid tumors (ClinicalTrials.gov identifier NCT01902173). METHODS: Patients with BRAF V600E/V600K-mutant solid tumors received oral dabrafenib at 150 mg twice daily with dose escalation of oral uprosertib starting at 50 mg daily, or, in the triplet cohorts, with dose escalation of both oral trametinib starting at 1.5 mg daily and oral uprosertib starting at 25 mg daily. Dose-limiting toxicities (DLTs) were assessed within the first 56 days of treatment. Radiographic responses were assessed at 8-week intervals. RESULTS: Twenty-seven patients (22 evaluable) were enrolled in parallel doublet and triplet cohorts. No DLTs were observed in the doublet cohorts (N = 7). One patient had a DLT at the maximum administered dose of triplet therapy (dabrafenib 150 mg twice daily and trametinib 2 mg daily plus uprosertib 75 mg daily). Three patients in the doublet cohorts had partial responses (including one who had BRAF inhibitor-resistant melanoma). Two patients in the triplet cohorts had a partial response, and one patient had an unconfirmed partial response. Pharmacokinetic data suggested reduced dabrafenib and dabrafenib metabolite exposure in patients who were also exposed to both trametinib and uprosertib, but not in whose who were exposed to uprosertib without trametinib. CONCLUSIONS: Concomitant inhibition of both the MAPK and PI3K-AKT pathways for the treatment of BRAF-mutated cancers was well tolerated, leading to objective responses, but higher level drug-drug interactions affected exposure to dabrafenib and its metabolites.

Efficacy of Ganshuang granules on non-alcoholic fatty liver and underlying mechanism: a network pharmacology and experimental verification.

OBJECTIVE: To investigate the potential pharmacological mechanisms of Ganshuang granules (, GSG) in treating non-alcoholic fatty liver (NAFLD). METHODS: All the active components and targets of GSG were retrieved from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform. Protein-Protein interaction network, Kyoto Encyclopedia of Genes and Genomes and Gene Ontology function annotation of common targets were analyzed to predict the mechanisms of action of GSG in the treatment of NAFLD. Then, the mouse models of NAFLD were constructed in a diet-induced manner and treated with GSG. The levels of interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-α) and phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) pathway-related proteins in the liver of mice in each group were measured by enzyme linked immunosorbent assay and Western blot, respectively. RESULTS: Network pharmacology revealed a total of 159 potential targets of GSG for the treatment of NAFLD. Functional enrichment analysis indicated that the PI3K/AKT signaling pathway may be involved during GSG treatment of NAFLD. Further experiments showed that the significantly decreased alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total cholesterol, triglyceride and low-density lipoprotein cholesterol levels in NAFLD model mice serum after GSG treatment, as well as the expression levels of IL-6 and TNF-α in the liver. Furthermore, drug intervention increased the protein expression levels of phosphorylated-PI3K (P-PI3K) and P-AKT in the liver of the model group mice, and decreased the protein expression level of sterol regulatory element-binding protein 1. CONCLUSION: We found that GSG is effective in treating NAFLD and the potential therapeutic targets may be involved in PI3K/AKT signaling pathway.

Mast cells in oral lichen planus and oral lichenoid lesions related to dental amalgam contact

Abstract The aim of this study was to analyze the expression of mast cell markers toluidine blue, c-kit, and tryptase and presence of mononuclear inflammatory cells in oral lichen planus (OLP) and oral lichenoid lesions related to dental amalgam. Nineteen specimens of OLP, OLLC, and healthy oral mucosa were selected. Mononuclear inflammatory cells were analyzed. Histochemical and immunohistochemical analyses were performed using toluidine blue, anti-c-kit and anti-tryptase reagents, and the results were quantified in areas A and B of connective tissue. Mast cells of all OLP and OLLC samples were positive for toluidine blue, c-kit, and tryptase. The density of toluidine blue+, c-kit+ and tryptase+ mast cells was higher in tissue with OLP and OLLC compared with healthy controls (p < 0.05). No difference was noted in mast cells density between OLP and OLLC (p > 0.05). The density of tryptase+ mast cells was higher in the subepithelial region (area A) than the region below it (Area B) in OLLC (p = 0.047). The mononuclear inflammatory cell density was higher in OLLC compared to OLP, but without statistical significance (p > 0.05). A positive statistical correlation was found between mononuclear immune cells and density of c-kit+ and tryptase+ mast cells in OLP (r = 0.943 and r = 0.886, respectively). Our data demonstrate that the etiopathogenesis process of OLP and OLLC modulates the expansion and degranulation of mast cells; mast cells density, however, was similar between OLP and OLLC. The distribution of mast cells appears to vary along the lamina propria.

Paraquat and Parkinson's Disease: The Molecular Crosstalk of Upstream Signal Transduction Pathways Leading to Apoptosis.

Parkinson's disease (PD) is a heterogeneous disease involving a complex interaction between genes and the environment that affects various cellular pathways and neural networks. Several studies have suggested that environmental factors such as exposure to herbicides, pesticides, heavy metals, and other organic pollutants are significant risk factors for the development of PD. Among the herbicides, paraquat has been commonly used, although it has been banned in many countries due to its acute toxicity. Although the direct causational relationship between paraquat exposure and PD has not been established, paraquat has been demonstrated to cause the degeneration of dopaminergic neurons in the substantia nigra pars compacta. The underlying mechanisms of the dopaminergic lesion are primarily driven by the generation of reactive oxygen species, decrease in antioxidant enzyme levels, neuroinflammation, mitochondrial dysfunction, and ER stress, leading to a cascade of molecular crosstalks that result in the initiation of apoptosis. This review critically analyses the crucial upstream molecular pathways of the apoptotic cascade involved in paraquat neurotoxicity, including mitogenactivated protein kinase (MAPK), phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/AKT, mammalian target of rapamycin (mTOR), and Wnt/ß-catenin signaling pathways.

Antitumor Activity of Ziziphus Jujube Fruit Extracts in KG-1 and NALM-6 Acute Leukemia Cell Lines.

Background : Ziziphus jujube Mill. belongs to the Rhamnaceae family. It has been reported to have a variety of biological activities such as antitumor, antioxidant, and anti-inflammatory effects. This study investigates the antiproliferative effect of Ziziphus jujube on KG-1 and NALM-6 acute leukemia cell lines. Materials and Methods : In this experimental study, the aqueous, ethyl acetate, and hydroalcoholic extracts of the Ziziphus jujube were prepared. Total phenolic and flavonoid components were detected because the presence of these compounds is associated with antioxidant and anticancer effects. Different concentrations of extracts were prepared, and KG-1 and NALM-6 cell lines were treated with them at 12, 24, 36, and 48 hours. Cell viability and IC50 values of the extracts were calculated using MTT assays. BD Cycle TEST PLUS DNA Kit was used for cell cycle progression analysis. Bcl2, Bax, and caspase-3 mRNA expressions were also assessed. Results : Cell viability decreased in a concentration-dependent manner. The best efficacy belonged to the ethyl acetate extract. Investigation of cell cycle progression demonstrated that the number of G0/G1 cells enhanced and the number of G2/M cells decreased when the ethyl acetate extract was applied in its IC50 concentration. A considerable increase in Caspase-3 and Bax and a decrease in Bcl2 gene expression were detected in molecular examination. Conclusion : According to our research, Ziziphus jujube ethyl acetate extract has antitumor properties on KG-1 and NALM-6 cell lines, possibly through induction of apoptosis and cell cycle regulation.

The association of BRAF V600E gene mutation with proliferative activity and histopathological characteristics of congenital melanocytic nevi in children

Abstract Background: A lot of congenital melanocytic nevi (CMN) carry the somatic mutation in the oncogene BRAF V600E. But the detailed histopathologic characteristics and the proliferative activity of CMN with BRAF V600E gene mutation have not been systematically documented. Objective: To identify the proliferative activity and histopathological features correlating them with BRAF V600E gene mutation status in CMN. Methods: CMN were retrospectively identified from the laboratory reporting system. Mutations were determined by Sanger sequencing. The CMN were divided into a mutant group and control group according to whether there was BRAF gene mutation and were strictly matched according to gender, age, nevus size, and location. Histopathological analysis, analysis of Ki67 expression by immunohistochemistry and laser confocal fluorescence microscopy were performed. Results: The differences in Ki67 index, the depth of nevus cell involvement and the number of nevus cell nests between the mutant group and the control group was statistically significant, with p-values of 0.041, 0.002 and 0.007, respectively. Compared with BRAFV600E negative nevi, BRAF V600E positive nevi often exhibited predominantly nested intraepidermal melanocytes, and larger junctional nests, but the difference in this datasets were not statistically significant. The number of nests (p = 0.001) was positively correlated with the proportion of Ki67 positive cells. Study limitations: A small sample of patients were included and there was no follow-up. Conclusions: BRAF V600E gene mutations were associated with high proliferative activity and distinct histopathological features in congenital melanocytic nevi.

Dihydroaustrasulfone alcohol induces apoptosis in nasopharyngeal cancer cells by inducing reactive oxygen species-dependent inactivation of the PI3K/AKT pathway.

Dihydroaustrasulfone alcohol (DA), the synthetic precursor of a natural compound (austrasulfone) isolated from the coral species Cladiella australis, has shown cytotoxic effects against cancer cells. However, it is unknown whether DA has antitumor effects on nasopharyngeal carcinoma (NPC). In this study, we determined the antitumor effects of DA and investigated its mechanism of action on human NPC cells. The MTT assay was used to determine the cytotoxic effect of DA. Subsequently, apoptosis and reactive oxygen species (ROS) analyses were performed by using flow cytometry. Apoptotic and PI3K/AKT pathway-related protein expression was determined using Western blotting. We found that DA significantly reduced the viability of NPC-39 cells and determined that apoptosis was involved in DA-induced cell death. The activity of caspase-9, caspase-8, caspase-3, and PARP induced by DA suggested caspase-mediated apoptosis in DA-treated NPC-39 cells. Apoptosis-associated proteins (DR4, DR5, FAS) in extrinsic pathways were also elevated by DA. The enhanced expression of proapoptotic Bax and decreased expression of antiapoptotic BCL-2 suggested that DA mediated mitochondrial apoptosis. DA reduced the expression of pPI3K and p-AKT in NPC-39 cells. DA also reduced apoptosis after introducing an active AKT cDNA, indicating that DA could block the PI3K/AKT pathway from being activated. DA increased intracellular ROS, but N-acetylcysteine (NAC), a ROS scavenger, reduced DA-induced cytotoxicity. NAC also reversed the chances in pPI3K/AKT expression and reduced DA-induced apoptosis. These findings suggest that ROS-mediates DA-induced apoptosis and PI3K/AKT signaling inactivation in human NPC cells.

Does BRAF V600E mutation affect recurrence rate of ameloblastomas? Systematic review and meta-analysis.

OBJECTIVE: The objective of this systematic review with meta-analysis was to critically evaluate the available data on the association of the BRAF V600E mutation and recurrence rate of ameloblastomas. MATERIALS AND METHODS: This systematic review was registered in Prospero (CRD42020183645) and performed based on the PRISMA statement. A comprehensive search in PubMed, Web of Science, Scopus and Cochrane Library databases was performed in order to answer the question "Does BRAF V600E mutation affect recurrence rate of ameloblastomas?" Methodological quality and risk of bias of the selected studies were assessed with JBI Critical Appraise Tool. Meta-analysis of quantitative data was conducted with RevMan 5.3 and Jamovi 2.3. RESULTS: The initial search identified 302 articles, and 21 met the inclusion criteria. A total of 855 subjects with ameloblastoma were included in the analysis. The pooled measures for frequency of BRAF V600E mutation was 65.30% (95% CI: 0.56-0.75; p < .001; I2 = 90.85%; τ = 0.205; p < .001), and the pooled recurrence rate was 25.30% (95% CI: 0.19-0.31; p < .001; I2 = 79.44%; τ = 0.118; p < .001). No differences in recurrence rate were observed between the BRAF V600E and wild type BRAF ameloblastomas, with a pooled Odds Ratio of 0.93 (95% CI: 0.56-1.54; p = .78; I2 = 31%; p = .09). CONCLUSIONS: BRAF V600E mutation is a frequent event in ameloblastomas, but does not increase nor reduce its recurrence rate, and thus have a limited value in predicting its prognosis.

[Molecular pathology of colorectal cancer]. / Molekularpathologie kolorektaler Karzinome.

In recent years, the treatment of colorectal carcinoma has experienced increasing individualization. In addition to RAS and BRAF mutational status that is firmly established in routine diagnostics, new therapeutic options evolved based on MSI and HER2 status as well as primary tumour localization. Offering the best targeted options in therapy requires new evidence-based decision-making algorithms regarding timing and scope of molecular pathological diagnostics in order for patients to receive an optimized therapy according to current treatment guidelines. New targeted therapies, some of which are about to be approved and for which pathology has to provide new molecular pathological biomarkers, will also play an increasingly important role in the future.

Association between macrocalcification and papillary thyroid carcinoma and corresponding valuable diagnostic tool: retrospective study.

BACKGROUND: Microcalcifications are suggested to be an indicator of thyroid malignancy, especially for papillary thyroid carcinoma (PTC), nonetheless, the association between macrocalcification and PTC is underexplored. Furthermore, screening methods like ultrasonography and ultrasound-guided fine needle aspiration biopsy (US-FNAB) are limited in evaluating macro-calcified thyroid nodules. Thus, we aimed to investigate the relationship between macrocalcification and PTC. We also explored the diagnostic efficiency of US-FNAB and proto-Oncogene Proteins B-raf V600E (BRAF V600E) mutation in macro-calcified thyroid nodules evaluation. METHODS: A retrospective research of 2645 thyroid nodules from 2078 participants was performed and divided into three groups as non-, micro-, and macro-calcified for further PTC incidence comparison. Besides, a total of 100 macro-calcified thyroid nodules with both results of US-FNAB and BRAF V600E mutation were screened out for subsequent evaluation of diagnostic efficiency. RESULTS: Compared to non-calcification, macrocalcification showed a significantly higher incidence of PTC (31.5% vs. 23.2%, P<0.05). Additionally, when compared with a single US-FNAB, the combination of US-FNAB and BRAF V600E mutation showed better diagnostic efficiency in diagnosing macro-calcified thyroid nodule (area under the curve (AUC) 0.94 vs. 0.84, P=0.03), with a significantly higher sensitivity (100.0% vs. 67.2%, P<0.01) and a comparable standard of specificity (88.9% vs. 100.0%, P=0.13). CONCLUSIONS: Occurrence of macrocalcification in thyroid nodules may suggest a high risk of PTC, and the combination of US-FNAB and BRAF V600E showed a greater value in identifying macro-calcified thyroid nodules, especially with significantly higher sensitivity. TRIAL REGISTRATION: The Ethics Committee of The First Affiliated Hospital of Wenzhou Medical University (2018-026).

The association of BRAF V600E gene mutation with proliferative activity and histopathological characteristics of congenital melanocytic nevi in children.

BACKGROUND: A lot of congenital melanocytic nevi (CMN) carry the somatic mutation in the oncogene BRAF V600E. But the detailed histopathologic characteristics and the proliferative activity of CMN with BRAF V600E gene mutation have not been systematically documented. OBJECTIVE: To identify the proliferative activity and histopathological features correlating them with BRAF V600E gene mutation status in CMN. METHODS: CMN were retrospectively identified from the laboratory reporting system. Mutations were determined by Sanger sequencing. The CMN were divided into a mutant group and control group according to whether there was BRAF gene mutation and were strictly matched according to gender, age, nevus size, and location. Histopathological analysis, analysis of Ki67 expression by immunohistochemistry and laser confocal fluorescence microscopy were performed. RESULTS: The differences in Ki67 index, the depth of nevus cell involvement and the number of nevus cell nests between the mutant group and the control group was statistically significant, with p-values of 0.041, 0.002 and 0.007, respectively. Compared with BRAF V600E negative nevi, BRAF V600E positive nevi often exhibited predominantly nested intraepidermal melanocytes, and larger junctional nests, but the difference in this data sets were not statistically significant. The number of nests (p = 0.001) was positively correlated with the proportion of Ki67 positive cells. STUDY LIMITATIONS: A small sample of patients were included and there was no follow-up. CONCLUSIONS: BRAF V600E gene mutations were associated with high proliferative activity and distinct histopathological features in congenital melanocytic nevi.

Development of a Prognostic Scoring System using MYC Expression and Soluble Interleukin Receptor -2 level for Diffuse Large B-cell Lymphoma.

Background: Diffuse large B-cell lymphoma, not otherwise specified (DLBCL-NOS), is the most frequent type of lymphoid neoplasm. Methods: We investigated the relationships between clinical factors of DLBCL-NOS and MYC immunohistochemistry (IHC) staining. Results: A total of 110 patients diagnosed with DLBCL-NOS from 2012 to 2020 at Tottori University Hospital and treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) chemotherapy were included. IHC staining of MYC in formalin-fixed, paraffin-embedded tumor specimens was performed, and ROC-curve analysis revealed the cut-off value of the MYC positive rate as 55%. The 2-year overall survival (OS) rates of the MYC-negative and -positive groups were 84.7% vs 57.7% (P = 0.0091), and the progression-free survival rates were 77.8% vs 54.7% (P = 0.016), respectively. Multivariate analysis for OS showed prognostic significance of MYC positivity [hazards ratio (HR): 2.496; P = 0.032], and serum levels of soluble interleukin-2 receptor (sIL-2R) > 2000 U/mL (HR: 3.950; P = 0.0019), as well as age > 75 (HR: 2.356; P = 0.068). The original scoring system was developed based on these findings. By assigning one point to each item, age (> 75), MYC positivity, and sIL-2R level (> 2000), all patients were classified into three risk categories: group 1 (0 points), group 2 (1 point), and group 3 (2-3 points). The 2-year survival rates were 100%, 83.0%, and 47.1% for the groups 1, 2, and 3, respectively (P < 0.0001). Conclusion: We suggest that a prognostic scoring system using MYC expression and soluble interleukin receptor -2 level is useful for the prediction of prognosis, contributing to further stratification in DLBCL-NOS.

BRAF inhibitor cessation prior to disease progression in metastatic melanoma: Long-term outcomes.

BACKGROUND: BRAF mutant melanoma treated with BRAF ± MEK inhibitor (targeted therapy) has a high response rate; however, most patients progress (PD). Some patients have durable response, but it is unknown whether treatment can be discontinued in these patients. We describe the recurrence risk, progression patterns, response to subsequent treatment, and survival of patients with advanced melanoma who ceased targeted therapy prior to PD. PATIENTS AND METHODS: Ninety-four patients who ceased targeted therapy without progression were identified retrospectively from 11 centres: 45 were male; 81 V600E; 88 stage IV. Fifty-nine were treated with BRAF + MEK inhibitor, and 35 were treated with BRAF inhibitor alone. Median treatment duration was 29.6 months (range 0.36-77.9). At cessation, 67 were in complete response, 21 in partial response, and 2 stable disease. RESULTS: After median follow-up from cessation of 42.9 months (range 0.0-88.7), 36 (38%) progressed; median time to progression was 4.7 months (range 0.7-56.9); 30 (83%) were asymptomatic and 7 (19%) had new brain metastases. Progression rates did not differ by best response: 34% for complete response and 43% for partial response (P = 0.65). Treatment duration was strongly associated with risk of progression: Median treatment duration was 18.3 (range 0.85-65.7) months for those who progressed and 34.6 (range 0.36-77.9) months for those who did not (P = 0.0004). Twenty-two received further targeted therapy with 15 (68%) responses. CONCLUSION: Risk of progression after cessation of targeted therapy is strongly associated with treatment duration. Response to retreatment with targeted therapy is high.

Use of DNA-alkylating pyrrole-imidazole polyamides for anti-cancer drug sensitivity screening in pancreatic ductal adenocarcinoma.

BACKGROUND: Activating mutations of the KRAS occurs in >90% of pancreatic ductal adenocarcinoma (PDAC) cases. However, direct pharmacological targeting of the activated KRAS protein has been challenging. We previously reported that KR12, a DNA-alkylating pyrrole-imidazole polyamide designed to recognize the KRAS G12D/V mutation, showed an anti-tumor effect in colorectal cancer. In this study, we evaluated the anti-tumor effect of KR12 in PDAC. METHODS: KR12 was synthesized by an automated peptide synthesizer PSSM-8 and tested for anti-tumor effect in PDAC mouse models. RESULT: KR12 inhibited tumor growth in a spontaneous PDAC mouse model, although the anti-tumor activity appeared to be limited in a human PDAC xenograft model. We developed a pyrrole-imidazole polyamide screening process based on the hypothesis that genetic elements otherwise unaffected by KR12 could exert attenuating effects on KRAS-suppression-resistant PDAC. We identified RAD51 as a potential therapeutic target in human PDAC cells. A RAD51 inhibitor showed an inhibitory effect on cell growth and affected the cytotoxic activity of KR12 in PDAC cells. CONCLUSION: These data suggested that the simultaneous inhibition of RAD51 and mutant KRAS blockage would be an important therapeutic strategy for PDAC.

KIT genetic alterations in breast cancer.

AIMS: Activating somatic mutations or gene amplification of KIT result in constitutive activation of its receptor tyrosine kinase, which is targetable in various solid tumours. Here, we sought to investigate the presence of KIT genetic alterations in breast cancer (BC) and characterise the histological and genomic features of these tumours. METHODS: A retrospective analysis of 5,575 BCs previously subjected to targeted sequencing using the FDA-authorised Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Targets (MSK-IMPACT) assay was performed to identify BCs with KIT alterations. A histological assessment of KIT-altered BCs was conducted, and their repertoire of genetic alterations was compared with that of BCs lacking KIT genetic alterations, matched for age, histological type, oestrogen receptor/HER2 status and sample type. RESULTS: We identified 18 BCs (0.32%), including 9 primary and 9 metastatic BCs, with oncogenic/likely oncogenic genetic alterations affecting KIT, including activating somatic mutations (n=4) or gene amplification (n=14). All KIT-altered BCs were of high histological grade, although no distinctive histological features were observed. When compared with BCs lacking KIT genetic alterations, no distinctive genetic features were identified. In two metastatic KIT-altered BCs in which the matched primary BC had also been analysed by MSK-IMPACT, the KIT mutations were found to be restricted to the metastatic samples, suggesting that they were late events in the evolution of these cancers. CONCLUSIONS: KIT genetic alterations are vanishingly rare in BC. KIT-altered BCs are of high grade but lack distinctive histological features. Genetic alterations in KIT might be late events in the evolution and/or progression of BC.

Significance of BRAF V600E mutation in prediction of the efficacy of apatinib for radioactive iodine-refractory differentiated thyroid cancer / 中华核医学与分子影像杂志

Objective:To investigate the significance of B-Raf proto-oncogene, serine/threonine kinase (BRAF) V600E mutation in the prediction of response to apatinib treatment in advanced radioactive iodine-refractory differentiated thyroid cancer (RAIR-DTC). Methods:Twenty patients (10 males, 10 females, age: 51.5(46.3, 65.0) years) with advanced RAIR-DTC from Peking Union Medical College Hospital between March 2016 and March 2023 were retrospectively enrolled, and all patients were treated with apatinib and underwent genetic sequencing (including BRAF V600E and telomerase reverse transcriptase (TERT) promoter). The serological and imaging data, progression-free survival (PFS) and overall survival (OS) data were collected during apatinib treatment. The Kaplan-Meier survival analysis (log-rank test) was performed, and Mann-Whitney U test were used to analyze the differences of duration of response (DOR) between mutation group and wild-type group. Then univariate and multivariate Cox regression analyses were conducted. Results:The PFS (35.3 vs 9.2 months, χ2=7.53, P=0.006) and DOR (25.8(7.4, 35.2) vs 8.2(2.5, 13.4) months, U=23.00, P=0.046) of the BRAF V600E mutation group were longer than those of the wild-type group. Univariate Cox regression analysis showed that the BRAF V600E mutation group had better PFS benefit (hazard ratio ( HR)=0.22 (95% CI: 0.06-0.72), P=0.013), and the risk of disease progression or death in patients with lung metastasis and bone or brain metastasis was 3.06(95% CI: 1.10-8.54, P=0.033) times higher than that in patients with lung metastasis alone. Further, multivariate cox regression analysis showed that only BRAF V600E mutation was an independent predictor of PFS ( HR=0.23 (95% CI: 0.07-0.80), P=0.021), suggesting that RAIR-DTC patients with BRAF V600E mutation might have better efficacy of apatinib. There was no significant difference in PFS ( χ2=1.34, P=0.247) and OS ( χ2=0.19, P=0.664) between TERT promoter mutation group and wild-type group. Conclusion:RAIR-DTC patients with BRAF V600E mutation have longer PFS and DOR after apatinib treatment than those with BRAF V600E wild-type, suggesting that BRAF V600E may be a potential biomarker to guide tyrosine kinase inhibitor (TKI) therapy and help to refine TKI treatment indications.