Immunohistochemistry Screening of Different Tyrosine Kinase Receptors in Canine Solid Tumors-Part I: Proposal of a Receptor Panel to Predict Therapies.

The use of tyrosine kinase inhibitors (TKI) has been growing in veterinary oncology and in the past few years several TKI have been tested in dogs. However, different from human medicine, we lack strategies to select patients to be treated with each TKI. Therefore, this study aimed to screen different tumor subtypes regarding TKI target immunoexpression as a predictor strategy to personalize the canine cancer treatment. It included 18 prostatic carcinomas, 36 soft tissue sarcomas, 20 mammary gland tumors, 6 urothelial bladder carcinomas, and 7 tumors from the endocrine system. A total of 87 patients with paraffin blocks were used to perform immunohistochemistry (IHC) of human epidermal growth factor receptor 2 (HER-2), epidermal growth factor receptors 1 (EGFR1), vascular endothelial growth factor receptor 2 (VEGFR-2), platelet derived growth factor receptor beta (PDGFR-ß), c-KIT, and extracellular signal-regulated kinase 1/2 (ERK1/ERK2). The immunohistochemical screening revealed a heterogeneous protein expression among histological types with mesenchymal tumors showing the lowest expression level and carcinomas the highest expression. We have demonstrated by IHC screening that HER2, EGFR1, VEGFR-2, PDGFR-ß and ERK1/ERK2 are commonly overexpressed in dogs with different carcinomas, and KIT expression is considered relatively low in the analyzed samples.

Importance of Testing for ROS1 Rearrangements in Non-Small Cell Lung Cancer in the Era of Targeted Therapy in a Latin American Country.

Purpose: Lung cancer is the leading cause of cancer-related deaths worldwide. However, with the optimization of screening strategies and advances in treatment, mortality has been decreasing in recent years. In this study, we describe non-small cell lung cancer patients diagnosed between 2021 and 2022 at a high-complexity hospital in Latin America, as well as the immunohistochemistry techniques used to screen for ROS1 rearrangements, in the context of the recent approval of crizotinib for the treatment of ROS1 rearrangements in non-small cell lung cancer in Colombia. Methods: A descriptive cross-sectional study was conducted. Sociodemographic, clinical, and molecular pathology information from non-small cell lung cancer individuals who underwent immunohistochemistry to detect ROS1 rearrangements between 2021 and 2022 at Fundación Valle del Lili (Cali, Colombia) was recorded. The clinical outcomes of confirmed ROS1 rearrangements in non-small cell lung cancer patients were reported. Results: One hundred and thirty-six patients with non-small cell lung cancer were included. The median age at diagnosis was 69.8 years (interquartile range 61.9-77.7). At diagnosis, 69.8% (n = 95) were at stage IV. ROS1 immunohistochemistry was performed using the monoclonal D4D6 antibody clone in 54.4% (n = 74) of the cases, while 45.6% (n = 62) were done with the monoclonal SP384 antibody clone. Two patients were confirmed to have ROS1 rearrangements in non-small cell lung cancer using next-generation sequencing and received crizotinib. On follow-up at months 5.3 and 7.0, one patient had a partial response, and the other had oligo-progression, respectively. Conclusion: Screening for ROS1 rearrangements in non-small cell lung cancer is imperative, as multiple prospective studies have shown improved clinical outcomes with tyrosine kinase inhibitors. Given the recent approval of crizotinib in Colombia, public health policies must be oriented toward early detection of driver mutations and prompt treatment. Additionally, future approvals of newly tested tyrosine kinase inhibitors should be anticipated.

Complete response to capmatinib in a patient with metastatic lung adenocarcinoma harboring CD47-MET fusion: a case report.

Comprehensive genomic profiling is highly recommended for treatment decision in nonsquamous, non-small cell lung cancer (NSCLC). However, rare genomic alterations are still being unveiled, with scarce data to guide therapy. Herein, we describe the treatment journey of a 56-year-old, never-smoker Caucasian woman with a metastatic NSCLC harboring a CD47-MET fusion, initially classified as a variant of unknown significance. She had undergone 3 lines of therapy over the course of 3 years, including chemotherapy, immunotherapy, and anti-angiogenic therapy. After reanalysis of her next-generation sequencing data in our service, the fusion was reclassified as likely oncogenic. The patient was started with fourth-line capmatinib, with a good tolerance so far and a complete metabolic response in the active sites of disease, currently ongoing for 18 months. In conclusion, we highlight the sensitivity of a novel MET fusion to capmatinib and emphasize the need for comprehensive panels in NSCLC and molecular tumor board discussions with specialized centers when rare findings arise.

vNARs as Neutralizing Intracellular Therapeutic Agents: Glioblastoma as a Target.

Glioblastoma is the most prevalent and fatal form of primary brain tumors. New targeted therapeutic strategies for this type of tumor are imperative given the dire prognosis for glioblastoma patients and the poor results of current multimodal therapy. Previously reported drawbacks of antibody-based therapeutics include the inability to translocate across the blood-brain barrier and reach intracellular targets due to their molecular weight. These disadvantages translate into poor target neutralization and cancer maintenance. Unlike conventional antibodies, vNARs can permeate tissues and recognize conformational or cryptic epitopes due to their stability, CDR3 amino acid sequence, and smaller molecular weight. Thus, vNARs represent a potential antibody format to use as intrabodies or soluble immunocarriers. This review comprehensively summarizes key intracellular pathways in glioblastoma cells that induce proliferation, progression, and cancer survival to determine a new potential targeted glioblastoma therapy based on previously reported vNARs. The results seek to support the next application of vNARs as single-domain antibody drug-conjugated therapies, which could overcome the disadvantages of conventional monoclonal antibodies and provide an innovative approach for glioblastoma treatment.

Investigation of the impact of AXL, TLR3, and STAT2 in congenital Zika syndrome through genetic polymorphisms and protein-protein interaction network analyses.

INTRODUCTION: Zika virus (ZIKV) is a human teratogen that causes congenital Zika syndrome (CZS). AXL, TLR3, and STAT2 are proteins involved in the ZIKV's entry into cells (AXL) and host's immune response (TLR3 and STAT2). In this study, we evaluated the role of genetic polymorphisms in these three genes as risk factors to CZS, and highlighted which proteins that interact with them could be important for ZIKV infection and teratogenesis. MATERIALS AND METHODS: We evaluate eighty-eight children exposed to ZIKV during the pregnancy, 40 with CZS and 48 without congenital anomalies. The evaluated polymorphisms in AXL (rs1051008), TLR3 (rs3775291), and STAT2 (rs2066811) were genotyped using TaqMan® Genotyping Assays. A protein-protein interaction network was created in STRING database and analyzed in Cytoscape software. RESULTS: We did not find any statistical significant association among the polymorphisms and the occurrence of CZS. Through the analyses of the network composed by AXL, TLR3, STAT2 and their interactions targets, we found that EGFR and SRC could be important proteins for the ZIKV infection and its teratogenesis. CONCLUSION: In summary, our results demonstrated that the evaluated polymorphisms do not seem to represent risk factors for CZS; however, EGFR and SRC appear to be important proteins that should be investigated in future studies.

Anti-ROR1 CAR-T cells: Architecture and performance.

The receptor tyrosine kinase-like orphan receptor 1 (ROR1) is a membrane receptor that plays a key role in development. It is highly expressed during the embryonic stage and relatively low in some normal adult tissues. Malignancies such as leukemia, lymphoma, and some solid tumors overexpress ROR1, making it a promising target for cancer treatment. Moreover, immunotherapy with autologous T-cells engineered to express a ROR1-specific chimeric antigen receptor (ROR1 CAR-T cells) has emerged as a personalized therapeutic option for patients with tumor recurrence after conventional treatments. However, tumor cell heterogeneity and tumor microenvironment (TME) hinder successful clinical outcomes. This review briefly describes the biological functions of ROR1 and its relevance as a tumor therapeutic target, as well as the architecture, activity, evaluation, and safety of some ROR1 CAR-T cells used in basic research and clinical trials. Finally, the feasibility of applying the ROR1 CAR-T cell strategy in combination with therapies targeting other tumor antigens or with inhibitors that prevent tumor antigenic escape is also discussed. Clinical trial registration: https://clinicaltrials.gov/, identifier NCT02706392.

Involvement of Met receptor pathway in aggressive behavior of colorectal cancer cells induced by parathyroid hormone-related peptide.

BACKGROUND: Parathyroid hormone-related peptide (PTHrP) plays a key role in the development and progression of many tumors. We found that in colorectal cancer (CRC) HCT116 cells, the binding of PTHrP to its receptor PTHR type 1 (PTHR1) activates events associated with an aggressive phenotype. In HCT116 cell xenografts, PTHrP modulates the expression of molecular markers linked to tumor progression. Empirical evidence suggests that the Met receptor is involved in the development and evolution of CRC. Based on these data, we hypothesized that the signaling pathway trigged by PTHrP could be involved in the transactivation of Met and consequently in the aggressive behavior of CRC cells. AIM: To elucidate the relationship among PTHR1, PTHrP, and Met in CRC models. METHODS: For in vitro assays, HCT116 and Caco-2 cells derived from human CRC were incubated in the absence or presence of PTHrP (1-34) (10-8 M). Where indicated, cells were pre-incubated with specific kinase inhibitors or dimethylsulfoxide, the vehicle of the inhibitors. The protein levels were evaluated by Western blot technique. Real-time polymerase chain reaction (RT-qPCR) was carried out to determine the changes in gene expression. Wound healing assay and morphological monitoring were performed to evaluate cell migration and changes related to the epithelial-mesenchymal transition (EMT), respectively. The number of viable HCT116 cells was counted by trypan blue dye exclusion test to evaluate the effects of irinotecan (CPT-11), oxaliplatin (OXA), or doxorubicin (DOXO) with or without PTHrP. For in vivo tests, HCT116 cell xenografts on 6-wk-old male N:NIH (S)_nu mice received daily intratumoral injections of PTHrP (40 µg/kg) in 100 µL phosphate-buffered saline (PBS) or the vehicle (PBS) as a control during 20 d. Humanitarian slaughter was carried out and the tumors were removed, weighed, and fixed in a 4% formaldehyde solution for subsequent treatment by immunoassays. To evaluate the expression of molecular markers in human tumor samples, we studied 23 specimens obtained from CRC patients which were treated at the Hospital Interzonal de Graves y Agudos Dr. José Penna (Bahía Blanca, Buenos Aires, Argentina) and the Hospital Provincial de Neuquén (Neuquén, Neuquén, Argentina) from January 1990 to December 2007. Seven cases with normal colorectal tissues were assigned to the control group. Tumor tissue samples and clinical histories of patients were analyzed. Paraffin-embedded blocks from primary tumors were reviewed by hematoxylin-eosin staining technique; subsequently, representative histological samples were selected from each patient. From each paraffin block, tumor sections were stained for immunohistochemical detection. The statistical significance of differences was analyzed using proper statistical analysis. The results were considered statistically significant at P < 0.05. RESULTS: By Western blot analysis and using total Met antibody, we found that PTHrP regulated Met expression in HCT116 cells but not in Caco-2 cells. In HCT116 cells, Met protein levels increased at 30 min (P < 0.01) and at 20 h (P < 0.01) whereas the levels diminished at 3 min (P < 0.05), 10 min (P < 0.01), and 1 h to 5 h (P < 0.01) of PTHrP treatment. Using an active Met antibody, we found that where the protein levels of total Met decreased (3 min, 10 min, and 60 min of PTHrP exposure), the status of phosphorylated/activated Met increased (P < 0.01) at the same time, suggesting that Met undergoes proteasomal degradation after its phosphorylation/activation by PTHrP. The increment of its protein level after these decreases (at 30 min and 20 h) suggests a modulation of Met expression by PTHrP in order to improve Met levels and this idea is supported by our observation that the cytokine increased Met mRNA levels at least at 15 min in HCT116 cells as revealed by RT-qPCR analysis (P < 0.05). We then proceeded to evaluate the signaling pathways that mediate the phosphorylation/ activation of Met induced by PTHrP in HCT116 cells. By Western blot technique, we observed that PP1, a specific inhibitor of the activation of the proto-oncogene protein tyrosine kinase Src, blocked the effect of PTHrP on Met phosphorylation (P < 0.05). Furthermore, the selective inhibition of the ERK 1/2 mitogen-activated protein kinase (ERK 1/2 MAPK) using PD98059 and the p38 MAPK using SB203580 diminished the effect of PTHrP on Met phosphorylation/activation (P < 0.05). Using SU11274, the specific inhibitor of Met activation, and trypan blue dye exclusion test, Western blot, wound healing assay, and morphological analysis with a microscope, we observed the reversal of cell events induced by PTHrP such as cell proliferation (P < 0.05), migration (P < 0.05), and the EMT program (P < 0.01) in HCT116 cells. Also, PTHrP favored the chemoresistance to CPT-11 (P < 0.001), OXA (P < 0.01), and DOXO (P < 0.01) through the Met pathway. Taken together, these findings suggest that Met activated by PTHrP participates in events associated with the aggressive phenotype of CRC cells. By immunohistochemical analysis, we found that PTHrP in HCT116 cell xenografts enhanced the protein expression of Met (0.190 ± 0.014) compared to tumors from control mice (0.110 ± 0.012; P < 0.05) and of its own receptor (2.27 ± 0.20) compared to tumors from control mice (1.98 ± 0.14; P < 0.01). Finally, assuming that the changes in the expression of PTHrP and its receptor are directly correlated, we investigated the expression of both Met and PTHR1 in biopsies of CRC patients by immunohistochemical analysis. Comparing histologically differentiated tumors with respect to those less differentiated, we found that the labeling intensity for Met and PTHR1 increased and diminished in a gradual manner, respectively (P < 0.05). CONCLUSION: PTHrP acts through the Met pathway in CRC cells and regulates Met expression in a CRC animal model. More basic and clinical studies are needed to further evaluate the PTHrP/Met relationship.

c-Kit Induces Migration of Triple-Negative Breast Cancer Cells and Is a Promising Target for Tyrosine Kinase Inhibitor Treatment.

Triple-negative breast cancer (TNBC) is associated with a poor prognosis and the absence of targeted therapy. c-Kit, a receptor tyrosine kinase (RTK), is considered a molecular target for anticancer drugs. Tyrosine kinase inhibitors (TKIs) recognizing c-Kit are used for the treatment of c-Kit-expressing tumors. However, the expression, function, and therapeutic potential of c-Kit have been little explored in TNBC. Here, we studied the expression and effects of c-Kit in TNBC through in vitro and in silico analysis, and evaluated the response to TKIs targeting c-Kit. Analysis of TNBC cells showed the expression of functional c-Kit at the cell membrane. The stimulation of c-Kit with its ligand induced the activation of STAT3, Akt, and ERK1/2, increasing cell migration, but had no effect on cell proliferation or response to Doxorubicin. Analysis of public datasets showed that the expression of c-Kit in tumors was not associated with patient survival. Finally, TNBC cells were susceptible to TKIs, in particular the effect of Nilotinib was stronger than Doxorubicin in all cell lines. In conclusion, TNBC cells express functional c-Kit, which is a targetable molecule, and show a strong response to Nilotinib that may be considered a candidate drug for the treatment of TNBC.

Expression of EGFR isoform D is regulated by HER receptor activators in breast cancer cells.

Human epidermal growth factor receptor isoform D (EGFR; isoform D) is a soluble protein from a 3 kb alternate mRNA transcript that arises from the human EGFR gene. Several studies have identified this circulating isoform of EGFR as a potential diagnostic biomarker for the detection of early stage of cancers. While the expression of the full-length EGFR (isoform A) is regulated by its cognate ligand, EGF, as well as by phorbol myristate acetate (PMA), no studies have examined the factors regulating the expression of EGFR isoform D. In this study, using breast cancer cell lines, we show that the HER receptor ligands, EGF and neuregulin (NRG-1ß), as well as the phorbol ester, PMA, can increase the expression of EGFR isoform D, as well as isoform A. Our results, based on measurement of mRNA levels, suggest that EGF induced expression of both isoform A and isoform D occur through a mitogen activated protein kinase (MAPK)-dependent mechanism, and also suggest that protein kinase C is involved in PMA-induced regulation of both isoforms. We also demonstrate that NRG-1ß increases isoform A and isoform D expression via the MAPK-dependent pathway, but this regulation occurs independently of phosphatidylinositol 3-kinase/Akt activation. These results suggest that regulation of EGFR isoform A and isoform D expression occur using similar mechanisms. Despite commonalities in the transcriptional regulation of these two EGFR isoforms, the half-lives of these two transcripts is quite different. Moreover, EGFR isoform D, unlike isoform A, is not post-transcriptionally modulated by EGFR activators in the breast cancer cell line MDA-MB-468.

Clinical and CT patterns to predict EGFR mutation in patients with non-small cell lung cancer: A systematic literature review and meta-analysis.

PURPOSE: This study aims to determine if the presence of specific clinical and computed tomography (CT) patterns are associated with epidermal growth factor receptor (EGFR) mutation in patients with non-small cell lung cancer. METHODS: A systematic literature review and meta-analysis was carried out in 6 databases between January 2002 and July 2021. The relationship between clinical and CT patterns to detect EGFR mutation was measured and pooled using odds ratios (OR). These results were used to build several mathematical models to predict EGFR mutation. RESULTS: 34 retrospective diagnostic accuracy studies met the inclusion and exclusion criteria. The results showed that ground-glass opacities (GGO) have an OR of 1.86 (95%CI 1.34 -2.57), air bronchogram OR 1.60 (95%CI 1.38 - 1.85), vascular convergence OR 1.39 (95%CI 1.12 - 1.74), pleural retraction OR 1.99 (95%CI 1.72 - 2.31), spiculation OR 1.42 (95%CI 1.19 - 1.70), cavitation OR 0.70 (95%CI 0.57 - 0.86), early disease stage OR 1.58 (95%CI 1.14 - 2.18), non-smoker status OR 2.79 (95%CI 2.34 - 3.31), female gender OR 2.33 (95%CI 1.97 - 2.75). A mathematical model was built, including all clinical and CT patterns assessed, showing an area under the curve (AUC) of 0.81. CONCLUSIONS: GGO, air bronchogram, vascular convergence, pleural retraction, spiculated margins, early disease stage, female gender, and non-smoking status are significant risk factors for EGFR mutation. At the same time, cavitation is a protective factor for EGFR mutation. The mathematical model built acts as a good predictor for EGFR mutation in patients with lung adenocarcinoma.

Small cell lung cancer: an overview of the targets

Abstract Lung cancer is the leading cause of cancer deaths worldwide. Small cell lung cancer (SCLC) accounts for approximately 15% of all lung cancer cases. Despite a frequently good response to first-line treatment with chemotherapy and/or radiotherapy, early relapse occurs in the majority of patients and 5-year survival is only about 5%. This histological subtype of lung cancer is strongly associated with tobacco smoking. The behavior of SCLC is unique within solid tumors. Initially, it positively responds to chemotherapy or radiotherapy. However, at relapse, which occurs early in the majority of cases, the tumor is resistant to available therapy and eventually will cause the death of the patient. These results in an overall 5-year survival of approximately 5% for the entire population of patients diagnosed with SCLC. This dismal prognosis has not significantly changed in past years. There is an urgent need for discovery targets to select patients more prone to having a proper response to the treatment, avoiding to reduce their resistance and resulting the increase of overall and progression-free survivals.

Recent advances in PTP1B signaling in metabolism and cancer.

Protein tyrosine phosphorylation is one of the major post-translational modifications in eukaryotic cells and represents a critical regulatory mechanism of a wide variety of signaling pathways. Aberrant protein tyrosine phosphorylation has been linked to various diseases, including metabolic disorders and cancer. Few years ago, protein tyrosine phosphatases (PTPs) were considered as tumor suppressors, able to block the signals emanating from receptor tyrosine kinases. However, recent evidence demonstrates that misregulation of PTPs activity plays a critical role in cancer development and progression. Here, we will focus on PTP1B, an enzyme that has been linked to the development of type 2 diabetes and obesity through the regulation of insulin and leptin signaling, and with a promoting role in the development of different types of cancer through the activation of several pro-survival signaling pathways. In this review, we discuss the molecular aspects that support the crucial role of PTP1B in different cellular processes underlying diabetes, obesity and cancer progression, and its visualization as a promising therapeutic target.

Complex roles of discoidin domain receptor tyrosine kinases in cancer.

Discoidin domain receptors, DDR1 and DDR2 are members of the receptor tyrosine kinase (RTK) family that serves as a non-integrin collagen receptor and were initially identified as critical regulators of embryonic development and cellular homeostasis. In recent years, numerous studies have focused on the role of these receptors in disease development, in particular, cancer where they have been reported to augment ECM remodeling, invasion, drug resistance to facilitate tumor progression and metastasis. Interestingly, accumulating evidence also suggests that DDRs promote apoptosis and suppress tumor progression in various human cancers due to which their functions in cancer remain ill-defined and presents a case of an interesting therapeutic target. The present review has discussed the role of DDRs in tumorigenesis and the metastasis.

N­glycosylation and receptor tyrosine kinase signaling affect claudin­3 levels in colorectal cancer cells.

Changes in protein levels in different components of the apical junctional complex occur in colorectal cancer (CRC). Claudin­3 is one of the main constituents of tight junctions, and its overexpression can increase the paracellular flux of macromolecules, as well as the malignant potential of CRC cells. The aim of this study was to investigate the molecular mechanisms involved in the regulation of claudin­3 and its prognostic value in CRC. In silico evaluation in each of the CRC consensus molecular subtypes (CMSs) revealed that high expression levels of CLDN3 (gene encoding claudin­3) in CMS2 and CMS3 worsened the patients' long­term survival, whereas a decrease in claudin­3 levels concomitant with a reduction in phosphorylation levels of epidermal growth factor receptor (EGFR) and insulin­like growth factor 1 receptor (IGF1R) could be achieved by inhibiting N­glycan biosynthesis in CRC cells. We also observed that specific inactivation of these receptor tyrosine kinases (RTKs) led to a decrease in claudin­3 levels, and this regulation seems to be mediated by phospholipase C (PLC) and signal transducer and activator of transcription 3 (STAT3) in CRC cells. RTKs are modulated by their N­linked glycans, and inhibition of N­glycan biosynthesis decreased the claudin­3 levels; therefore, we evaluated the correlation between N­glycogenes and CLDN3 expression levels in each of the CRC molecular subtypes. The CMS1 (MSI immune) subtype concomitantly exhibited low expression levels of CLDN3 and N­glycogenes (MGAT5, ST6GAL1, and B3GNT8), whereas CMS2 (canonical) exhibited high gene expression levels of CLDN3 and N­glycogenes (ST6GAL1 and B3GNT8). A robust positive correlation was also observed between CLDN3 and B3GNT8 expression levels in all CMSs. These results support the hypothesis of a mechanism integrating RTK signaling and N­glycosylation for the regulation of claudin­3 levels in CRC, and they suggest that CLDN3 expression can be used to predict the prognosis of patients identified as CMS2 or CMS3.

Receptor tyrosine kinase activation induces free fatty acid 4 receptor phosphorylation, ß-arrestin interaction, and internalization.

FFA4 (Free Fatty Acid receptor 4, previously known as GPR120) is a G protein-coupled receptor that acts as a sensor of long-chain fatty acids, modulates metabolism, and whose dysfunction participates in endocrine disturbances. FFA4 is known to be phosphorylated and internalized in response to agonists and protein kinase C activation. In this paper report the modulation of this fatty acid receptor by activation of receptor tyrosine kinases. Cell-activation with growth factors (insulin, epidermal growth factor, insulin-like growth factor-I, and platelet-derived growth factor) increases FFA4 phosphorylation in a time- and concentration-dependent fashion. This effect was blocked by inhibitors of protein kinase C and phosphoinositide 3-kinase, suggesting the involvement of these kinases in it. FFA4 phosphorylation did not alter agonist-induced FFA4 calcium signaling, but was associated with decreased ERK 1/2 phosphorylation. In addition, insulin, insulin-like growth factor-I, epidermal growth factor, and to a lesser extent, platelet-derived growth factor, induce receptor internalization. This action of insulin, insulin-like growth factor I, and epidermal growth factor was blocked by inhibitors of protein kinase C and phosphoinositide 3-kinase. Additionally, cell treatment with these growth factors induced FFA4-ß-arrestin coimmunoprecipitation. Our results evidenced cross-talk between receptor tyrosine kinases and FFA4 and suggest roles of protein kinase C and phosphoinositide 3-kinase in such a functional interaction.

Strategies to overcome acquired resistance to EGFR TKI in the treatment of non-small cell lung cancer.

Epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI) represents a paradigm shift in the treatment of non-small cell lung cancer (NSCLC) patients and has been the first-line therapy in clinical practice. While erlotinib, gefitinib and afatinib have achieved superior efficacy in terms of progression-free survival and overall survival compared with conventional chemotherapy in NSCLC patients, most people inevitably develop acquired resistance to them, which presents another challenge in the treatment of NSCLC. The mechanisms of acquired resistance can be classified as three types: target gene mutation, bypass signaling pathway activation and histological transformation. And the most common mechanism is T790M which accounts for approximately 50% of all subtypes. Many strategies have been explored to overcome the acquired resistance to EGFR TKI. Continuation of EGFR TKI beyond progressive disease is confined to patients in asymptomatic stage when the EGFR addiction is still preserved in some subclones. While the combination of EGFR TKI and chemotherapy or other targeted agents has improved the survival benefit in EGFR TKI resistant patients, there are controversies within them. The next-generation EGFR TKI and immunotherapy represent two novel directions for overcoming acquired resistance and have achieved promising efficacy. Liquid biopsy provides surveillance of the EGFR mutation by disclosing the entire genetic landscape but tissue biopsy is still indispensable because of the considerable rate of false-negative plasma.

Economic evaluation of sunitinib versus pazopanib and best supportive care for the treatment of metastatic renal cell carcinoma in Chile: cost-effectiveness analysis and a mixed treatment comparison.

Background: Sunitinib and Pazopanib are two metastatic renal cell carcinoma (MRCC) treatment alternatives, however the health system in Chile does not consider coverage for any. The cost-effectiveness versus relevant comparator was assessed to support evidence-based decision making. Methods: A four health states Markov model was built: first, second line treatments, BSC and death. Benefits were measured in QALYs, and efficacy estimates were obtained from an indirect treatment comparison. A 10-year time horizon and a 3% undifferentiated discount rate were considered. Deterministic and probabilistic sensitivity analyses were performed. Results: The costs of treating MRCC with Sunitinib were higher than Pazopanib and BSC. When comparing Sunitinib versus Pazopanib, the incremental benefit is small favoring Sunitinib (0.03 QALYs). The base case scenario shows an average ICER of PA versus BSC of US$62,327.11/QALY and of US$85,885/QALY for Sunitinib versus Pazopanib. The ICER was most sensitive to the OS relative to BSC, where evidence was associated to important bias. Conclusions: Sunitinib or Pazopanib can be considered cost-effective if a 3 GDP per-capita threshold is assumed. The decision between SU or PA is highly sensitive to the price of the drugs, rather than the outcomes. Therefore, the decision might be made based on cost-minimization exercise.

Acute acalculous cholecystitis in a patient with metastatic renal cell carcinoma treated with sunitinib.

A 55-year old man was treated with sunitinib 50 mg/day for 4 weeks on and 2 weeks off, as a first-line therapy for metastatic renal cell carcinoma. During the fourth week of the first cycle, he was admitted to the Emergency Department with abdominal pain and vomiting. Acute acalculous cholecystitis was diagnosed. Sunitnib-associated cholecystitis is a rare adverse event previously reported in few cases. The mechanism behind this complication is not fully understood, although vascular endothelial dysfunction may play a role. The use of this drug is expanding in clinical oncology, and physicians should be aware of this life-threating adverse event.

Calix[6]arene bypasses human pancreatic cancer aggressiveness: downregulation of receptor tyrosine kinases and induction of cell death by reticulum stress and autophagy.

Pancreatic cancer ranks fourth among cancer-related causes of death in North America. Minimal progress has been made in the diagnosis and treatment of patients with late-stage tumors. Moreover, pancreatic cancer aggressiveness is closely related to high levels of pro-survival mediators, which can ultimately lead to rapid disease progression, resistance and metastasis. The main goal of this study was to define the mechanisms by which calix[6]arene, but not other calixarenes, efficiently decreases the aggressiveness of a drug resistant human pancreas carcinoma cell line (Panc-1). Calix[6]arene was more potent in reducing Panc-1 cell viability than gemcitabine and 5-fluorouracil. In relation to the underlying mechanisms of cytotoxic effects, it led to cell cycle arrest in the G0/G1 phase through downregulation of PIM1, CDK2, CDK4 and retinoblastoma proteins. Importantly, calix[6]arene abolished signal transduction of Mer and AXL tyrosine kinase receptors, both of which are usually overexpressed in pancreatic cancer. Accordingly, inhibition of PI3K and mTOR was also observed, and these proteins are positively modulated by Mer and AXL. Despite decreasing the phosphorylation of AKT at Thr308, calix[6]arene caused an increase in phosphorylation at Ser473. These findings in conjunction with increased BiP and IRE1-α provide a molecular basis explaining the capacity of calix[6]arene to trigger endoplasmic reticulum stress and autophagic cell death. Our findings highlight calix[6]arene as a potential candidate for overcoming pancreatic cancer aggressiveness. Importantly, we provide evidence that calix[6]arene affects a broad array of key targets that are usually dysfunctional in pancreatic cancer, a highly desirable characteristic for chemotherapeutics.