The E545K mutation of PIK3CA promotes gallbladder carcinoma progression through enhanced binding to EGFR

Comprehensive clinicopathological and genomic profiling of gallbladder cancer reveals actionable targets in half of patients

Gallbladder cancer (GBC) is a rare, highly aggressive malignancy with a 5-year survival rate of 5–10% in advanced cases, highlighting the need for more effective therapies. The aim of this study was to identify potentially actionable therapeutic targets for GBC. Specimens and clinicopathological data of 642 GBC patients, diagnosed between 2000 and 2019 were collected using the Dutch Pathology Registry (PALGA) and the Netherlands Cancer Registry. All cases were histologically reviewed and a subset was subjected to a comprehensive next generation sequencing panel. We assessed mutations and gene amplifications in a panel of 54 actionable genes, tumor-mutational burden (TMB), and microsatellite instability (MSI). Additionally, the entire cohort was screened for HER2, PD-L1, pan-TRK, and p53 expression with immunohistochemistry. Histopathological subtypes comprised biliary-type adenocarcinoma (AC, 69.6%), intestinal-type AC (20.1%) and other subtypes (10.3%). The median total TMB was 5.5 mutations/Mb (range: 0–161.1) and 17.7% of evaluable cases had a TMB of >10 mutations/Mb. MSI was observed in two cases. Apart from mutations in TP53 (64%), tumors were molecularly highly heterogeneous. Half of the tumors (50%) carried at least one molecular alteration that is targetable in other tumor types, including alterations in CDKN2A (6.0% biallelically inactivated), ERBB2 (9.3%) and PIK3CA (10%). Immunohistochemistry results correlated well with NGS results for HER2 and p53: Pearson r = 0.82 and 0.83, respectively. As half of GBC patients carry at least one potentially actionable molecular alteration, molecular testing may open the way to explore targeted therapy options for GBC patients.

The role of PI3K/AKT signaling pathway in gallbladder carcinoma

OBJECTIVES

The prognosis of gallbladder carcinoma (GBC) is poor, with a less than 5% five-year survival rate. Identifying the mechanisms underlying GBC occurrence and advancement is necessary to improve GBC patient prognosis and survival rates. The phosphatidylinositol 3-kinase (PI3K)/serine-threonine kinase (AKT) pathway is involved in cancer deterioration, tumor growth, cell proliferation, and distant metastasis. Studying the impacts of the PI3K/AKT pathway has resulted in the identification of key factors involved in GBC progression that might serve as therapeutic targets, promoting the development of new treatments.

METHODS

We reviewed recent literature exploring abnormal regulation of the PI3K/AKT pathway in gallbladder cancer, with a focus on abnormal RNA levels, protein level regulation, and drug treatment advances.

RESULTS

Further investigation of the regulation of small molecules and proteins by the PI3K/AKT pathway might ultimately provide new diagnostic or prognostic markers or cancer treatment targets. Recent studies have focused on RNA and proteins involved in the regulation of the cell cycle or cell movement in cancer progression via PI3K/AKT pathway, the use of anticancer drug combinations, or the anticancer effects of drugs not currently utilized for cancer treatment.

CONCLUSIONS

We herein review the known available molecules that affect the PI3K/AKT pathway in patients with GBC and the mechanisms of drug action associated with this pathway.

Case report: TP53 and RB1 loss may facilitate the transformation from lung adenocarcinoma to small cell lung cancer by expressing neuroendocrine markers

INTRODUCTION

Transformation from lung adenocarcinoma (LUAD) to small cell lung cancer (SCLC) is one of the mechanisms responsible for acquired EGFR-TKIs resistance. Although it rarely happens this event determines a rapid disease deterioration and needs specific treatment.

PATIENT AND METHOD

We report a case of 75-year-old LUAD female with a p.L858R mutation in Epidermal Growth Factor Receptor (EGFR) who presented with SCLC transformation after responding to first line osimertinib treatment for only 6 months. To understand the underlying molecular mechanism, we retrospectively sequenced the first (LUAD) and the second (SCLC) biopsy using a 56 multi-gene panel. Immunohistochemistry (IHC) staining and Fluorescence In Situ Hybridization (FISH) was applied to confirm the genetic aberrations identified.

RESULTS

EGFR p.E709A and p.L858R, Tumor Protein p53 (TP53) p.A159D and Retinoblastoma 1 (RB1) c.365-1G>A were detected in both the diagnostic LUAD and transformed SCLC samples. A high copy number gain for Proto-Oncogene C-Myc (MYC) and a Phosphoinositide 3-Kinase Alpha (PIK3CA) p.E545K mutation were found in the transformed sample specifically. Strong TP53 staining and negative RB1 staining were observed in both LUAD and SCLC samples, but FISH only identified MYC amplification in SCLC tissue.

CONCLUSION

We consider the combined presence of MYC amplification with mutations in TP53 and RB1 as drivers of SCLC transformation. Our results highlight the need to systematically evaluate TP53 and RB1 status in LUAD patients to offer a different therapeutic strategy.

Gallbladder Cancer: Current Insights in Genetic Alterations and Their Possible Therapeutic Implications

Due to the fast progression in molecular technologies such as next-generation sequencing, knowledge of genetic alterations in gallbladder cancer (GBC) increases. This systematic review provides an overview of frequently occurring genetic alterations occurring in GBC and their possible therapeutic implications. A literature search was performed utilizing PubMed, EMBASE, Cochrane Library, and Web of Science. Only studies reporting genetic alterations in human GBC were included. In total, data were extracted from 62 articles, describing a total of 3893 GBC samples. Frequently detected genetic alterations (>5% in >5 samples across all studies) in GBC for which targeted therapies are available in other cancer types included mutations in ATM, ERBB2, and PIK3CA, and ERBB2 amplifications. High tumor mutational burden (TMB-H) and microsatellite instability (MSI-H) were infrequently observed in GBC (1.7% and 3.5%, respectively). For solid cancers with TMB-H or MSI-H pembrolizumab is FDA-approved and shows an objective response rates of 50% for TMB-H GBC and 41% for MSI-H biliary tract cancer. Only nine clinical trials evaluated targeted therapies in GBC directed at frequently altered genes (ERBB2, ARID1A, ATM, and KRAS). This underlines the challenges to perform such clinical trials in this rare, heterogeneous cancer type and emphasizes the need for multicenter clinical trials.

Genetic and immune characteristics of sentinel lymph node metastases and multiple lymph node metastases compared to their matched primary breast tumours

BACKGROUND

Patients with breast cancer presenting with single lymph node metastasis (from a sentinel node) experience prolonged survival compared to patients with multiple lymph node metastases (≥3). However, little information is available on the genetic and immunological characteristics of breast cancer metastases within the regional lymph nodes as they progress from the sentinel lymph node (SLN) downstream to multiple regional lymph nodes (MLNs).

METHODS

Genomic profiling was performed using a next-generation sequencing panel covering 520 cancer-related genes in the primary tumour and metastatic lymph nodes of 157 female patients with breast cancer. We included primary tumours, metastatic lymph nodes and adjacent clinically normal lymph nodes (20 patients from the SLN group and 28 patients from the MLNs group) in the whole transcriptome analysis.

FINDINGS

The downstream metastatic lymph nodes (P = 0.029) and the primary breast tumours (P = 0.011) had a higher frequency of PIK3CA mutations compared to the SLN metastasis. We identified a distinct group of 14 mutations from single sentinel node metastasis and a different group of 15 mutations from multiple nodal metastases. Only 4 distinct mutations (PIK3CA, CDK4, NFKBIA and CDKN1B) were conserved in metastases from both lymph node settings. The tumour mutational burden (TMB) was significantly lower in single nodal metastasis compared to the paired primary breast cancer (P = 0.0021), while the decline in TMB did not reach statistical significance in the MLNs group (P = 0.083). In the gene set enrichment analysis, we identified 4 upregulated signatures in both primary tumour and nodal metastases from the MLNs group, including 3 Epithelial-mesenchymal transition(EMT) signatures and 1 angiogenesis signature. Both the CD8/Treg ratio and the CD8/EMT ratio were significantly higher in adjacent normal lymph nodes from patients with a single metastasis in the SLN compared with samples from the MLNs group (P = 0.045 and P = 0.023, respectively). This suggests that the immune defence from the MLNs patients might have a less favourable microenvironment, thus permitting multiple lymph nodes metastasis.

INTERPRETATION

Single lymph node metastases and multiple lymph node metastases have significant differences in their molecular profiles and immune profiles. The findings are associated with more aggressive tumour characteristics and less favourable immune charactoristics in patients with multiple nodal metastases compared to those with a single metastasis in the sentinel node.

FUNDING

This work was supported by funds from High-level Hospital Construction Project (DFJH201921), the National Natural Science Foundation of China (81902828 and 82002928), the Fundamental Research Funds for the Central Universities (y2syD2192230), and the Medical Scientific Research Foundation of Guangdong Province (B2019039).

Programmable One-Pot Enzymatic Reaction for Direct Fluorescence Detection of Ultralow-Abundance Mutations in the DNA Duplex

Sensitive detection of low-abundance driver mutations may provide valuable information for precise clinical treatment. Compared to next-generation sequencing and droplet digital PCR methods, fluorescent probes show great flexibility in rapid detection of specific mutations with high sensitivity and easily accessible instruments. However, existing approaches with fluorescent probes need an additional step to convert duplex DNA to single-stranded DNA (ssDNA) before the detection step, which increases the time, cost, and risk of loss of low-input target strands. In this work, we attempt to integrate the ssDNA-generation step with the subsequent detection into a programable one-pot reaction by employing lambda exonuclease (λ exo), a versatile nanopore nuclease which exercises different functions on different substrates. The capability of λ exo in discrimination of mismatched bases in 5'- FAM-ended 2 nt-unpaired DNA duplexes was first demonstrated. Specific fluorescent probes were developed for EGFR exon 19 E746-A750del and PIK3CA E545K mutations with discrimination factors as high as 8470 and 884, respectively. By mixing the probes and λ exo with the PCR products of cell-free circulating DNA extracted from plasma samples, the reaction was immediately initiated, which allowed sensitive detection of the two types of mutations at an abundance as low as 0.01% within less than 2 h. Compared to existing approaches, the new method has distinct advantages in simplicity, low cost, and rapidity. It provides a convenient tool for companion diagnostic tests and other routine analysis targeting genetic mutations in clinical samples.

miR-365 inhibits the progression of gallbladder carcinoma and predicts the prognosis of Gallbladder carcinoma patients

Gallbladder carcinoma (GBC) is one of the most common fatal biliary tract tumors in the world. Its 3-year survival rate is 30% and the recurrence rate remains very high. miR-365 was downregulated in numerous tumors and worked as tumor suppressor gene. However, the role of miR-365 in GBC was unclear. In this study, our results found that the expression of miR-365 in GBC tissues was reduced rather than that in non-cancerous tissues. miR-365 overexpression inhibited the proliferation, metastasis and expansion of GBC CSCs. Mechanically, bioinformatic and luciferase reporter analysis identified Ras-related C3 botulinum toxin substrate 1 (RAC1) as a direct target of miR-365. Overexpression of miR-365 in GBC cells reduced the RAC1 mRNA and protein expression. The special RAC1 inhibitor EHop-106 abolished the discrepancy of growth, metastasis and self-renewal ability between miR-365-overexpression GBC cells and their control cells, which further demonstrated that RAC1 was involved in miR-365-disrupted GBC cells growth, metastasis and self-renewal. More importantly, reduced expression of miR-365 was a predictor of poor prognosis of GBC patients. In conclusion, miR-365 inhibited GBC cell growth, metastasis and self-renewal capacity by directly targeting RAC1, and may therefore prove to be a novel prognosis biomarker for GBC patients.

Role of Sciellin in gallbladder cancer proliferation and formation of neutrophil extracellular traps

Apart from primary tumor development and metastasis, cancer-associated thrombosis is the second cause of cancer death in solid tumor malignancy. However, the mechanistic insight into the development of gallbladder cancer (GBC) and cancer-associated thrombosis remains unclear. This study aimed to investigate the mechanistic role of Sciellin (SCEL) in GBC cell proliferation and the development of venous thromboembolism. The expression level of SCEL was determined by immunohistochemical staining. Roles of SCEL in gallbladder cancer cell were determined by molecular and cell biology methods. SCEL was markedly upregulated in GBC and associated with advanced TNM stages and a poor prognosis. Furthermore, SCEL interacted with EGFR and stabilized EGFR expression that activates downstream PI3K and Akt pathway, leading to cell proliferation. In addition, SCEL induces tumor cell IL-8 production that stimulates the formation of neutrophil extracellular traps (NETs), accelerating thromboembolism. In xenografts, SCEL-expressing GBCs developed larger tumors and thrombosis compared with control cells. The present results indicate that SCEL promotes GBC cell proliferation and induces NET-associated thrombosis, thus serving as a potential therapeutic target.

PIK3CA Is Regulated by CUX1, Promotes Cell Growth and Metastasis in Bladder Cancer via Activating Epithelial-Mesenchymal Transition

PIK3CA is a key component of phosphatidylinositol 3-kinase (PI3K) pathway that its involvement in tumorigenesis has been revealed by previous research. However, its functions and potential mechanisms in bladder cancer are still largely undiscovered. Tissue microarray (TMA) with 66 bladder cancer patients was surveyed via immunohistochemistry to evaluate the level of PIK3CA and CUX1 and we found upregulation of PIK3CA in bladder cancer tissue and patients with higher level of PIK3CA presented with poorer prognosis. Overly expressed PIK3CA promoted growth, migration, invasion, and metastasis of bladder cancer cells and knockdown of PIK3CA had the opposite effect. Gain-of-function and loss-of-function studies showed that PIK3CA expression was facilitated by CUX1, leading to activation of epithelial-mesenchymal transition (EMT), accompanied by upregulated expression of Snail, β-catenin, Vimentin and downregulated expression of E-cadherin in the bladder cancer cell lines. Besides, over-expressed CUX1 could restore the expression of downregulated Snail, β-catenin, Vimentin and E-cadherin which was induced by PIK3CA knockdown. These results revealed that PIK3CA overexpression in bladder cancer was regulated by the transcription factor CUX1, and PIK3CA exerted its biological effects by activating EMT.

Case Report: Primary and Acquired Resistance Mechanisms of Nimotuzumab in Advanced Esophageal Squamous Cell Carcinoma Revealed by Targeted Sequencing

Esophageal squamous cell carcinoma (ESCC) is a deadly disease with a low 5-year survival rate. Anti-epidermal growth factor receptor (EGFR) therapy has been widely used in the treatment of malignancies, and chemotherapy regimens that include nimotuzumab have been confirmed to have satisfactory efficacy among esophageal carcinoma (EC) patients. However, a subpopulation of patients may develop resistance to nimotuzumab. Here, we report an advanced ESCC patient who experienced hyperprogressive disease induced by immune checkpoint inhibitors and was then treated with a chemotherapy regimen containing nimotuzumab. NGS examination of this patient demonstrated that PIK3CA mutation and a RICTOR amplification might participate in primary and acquired resistance to nimotuzumab, respectively, via the PI3K/AKT/mTOR signaling pathway.

Overview of current targeted therapy in gallbladder cancer

Gallbladder cancer (GBC) is rare, but is the most malignant type of biliary tract tumor. Unfortunately, only a small population of cancer patients is acceptable for the surgical resection, the current effective regimen; thus, the high mortality rate has been static for decades. To substantially circumvent the stagnant scenario, a number of therapeutic approaches owing to the creation of advanced technologic measures (e.g., next-generation sequencing, transcriptomics, proteomics) have been intensively innovated, which include targeted therapy, immunotherapy, and nanoparticle-based delivery systems. In the current review, we primarily focus on the targeted therapy capable of specifically inhibiting individual key molecules that govern aberrant signaling cascades in GBC. Global clinical trials of targeted therapy in GBC are updated and may offer great value for novel pathologic and therapeutic insights of this deadly disease, ultimately improving the efficacy of treatment.

Silencing ARAF Suppresses the Malignant Phenotypes of Gallbladder Cancer Cells

ARAF is a member of the RAF kinase family that is necessary for mitogen-activated protein kinase (MAPK) activation in various malignancies, including lung, colorectal, pancreatic, and breast cancers. As the most common biliary tract tumor, gallbladder cancer (GBC) seriously harms human health while the function of ARAF in GBC remains elusive. Here, we found that ARAF expression was upregulated in gallbladder cancer tissues. In vitro, ARAF silencing mediated by RNA interference effectively inhibited cell proliferation, colony formation, migration, and invasion of GBC cells. Moreover, knocking down ARAF suppressed tumor growth in vivo. Our results indicated that ARAF functions as an oncogene in GBC and, thus, could be a potential therapeutic target for GBC.

MUC16 C-terminal binding with ALDOC disrupts the ability of ALDOC to sense glucose and promotes gallbladder carcinoma growth

The MUC16 C-terminal (MUC16c) level is associated with tumor serum CA-125 levels, however, the roles remain unclear in gallbladder carcinoma (GBC). In this study, we found that MUC16c promoted glucose uptake and glycolysis for GBC cell proliferation. Mass spectrometry analysis suggested that MUC16c could combine with aldolase. The ALDOC mRNA and protein are overexpressed in GBC tumors. The IHC results also showed the consistent up-regulation of. ALDOC and MUC16c level in GBC tumor tissues than in peritumor tissues. We determined that MUC16c combining with ALDOC promoted ALDOC protein stability and disrupted the ability of ALDOC sensing glucose deficiency, which activated AMPK pathway and increased GBC cell proliferation. ALDOC knockdown significantly inhibited the glucose uptake and glycolysis induced by MUC16c. Our study established important roles of MUC16c promoting GBC cell glycolysis and proliferation and revealed the underlying mechanism of CA-125-related heavy tumor metabolic burden in GBC.

Role of PI3K/AKT pathway in cancer: the framework of malignant behavior

Given that the PI3K/AKT pathway has manifested its compelling influence on multiple cellular process, we further review the roles of hyperactivation of PI3K/AKT pathway in various human cancers. We state the abnormalities of PI3K/AKT pathway in different cancers, which are closely related with tumorigenesis, proliferation, growth, apoptosis, invasion, metastasis, epithelial-mesenchymal transition, stem-like phenotype, immune microenvironment and drug resistance of cancer cells. In addition, we investigated the current clinical trials of inhibitors against PI3K/AKT pathway in cancers and found that the clinical efficacy of these inhibitors as monotherapy has so far been limited despite of the promising preclinical activity, which means combinations of targeted therapy may achieve better efficacies in cancers. In short, we hope to feature PI3K/AKT pathway in cancers to the clinic and bring the new promising to patients for targeted therapies.

Targeting gallbladder cancer: a pathway based perspective

Gallbladder cancer (GBC) has a poor prognosis with a 5-year survival rate suggesting the need for more effective treatment strategies. Studying the cross-talk of several pathways involved in crucial cellular and biological processes such as cell growth, proliferation, migration and apoptosis would prove beneficial in identifying key players of GBC progression and targeting them. This review highlights several pathways known to be dysregulated in GBC onset and progression and describes known and potential targets. Within these pathways, there are proteins involved in the signalling cascade, which may be targeted as potential biomarkers and drug targets. Furthermore, the cross-talk of these pathways is investigated in the context of GBC and the implications thereof. A better understanding of the pathways involved in GBC pathogenesis will aid clinicians in the prognosis, diagnosis and treatment of patients. There are significant clinical implications of GBC pathway-based studies as they permit the understanding of onset and progression of the disease.

Clinical and Translational Research Challenges in Biliary Tract Cancers

BACKGROUND

Biliary Tract Cancers (BTC) are rare malignancies with a poor prognosis. There are many challenges encountered in treating these patients in daily practice as well as in clinical, translational and basic research.

OBJECTIVE

This review summarises the most relevant challenges in clinical and translational research in BTCs and suggests potential solutions towards an improvement in quality of life and outcomes of patients diagnosed with such malignancies.

FINDINGS

The main challenge is the low number of patients with BTCs, complicated by the aggressive natural behaviour of cancer and the lack of funding sources for research. In addition, the clinical characteristics of these patients and the specific cancer-related complications challenge clinical research and clinical trial recruitment. It is worth highlighting that BTCs are a group of different malignancies (cholangiocarcinoma, gallbladder cancer and ampullary cancer) rather than a unique homogeneous disease. These subgroups differ not only in molecular aspects, but also in clinical and demographic characteristics. In addition, tailored imaging and quality of life assessment are required to tackle some of the issues specific to BTCs. Finally, difficulties in tissue acquisition both in terms of biopsy size and inclusion of sufficient tumour within the samples, may adversely impact translational and basic research.

CONCLUSION

Increasing awareness among patients and clinicians regarding BTC and the need for further research and treatment development may address some of the main challenges in BTC research. International collaboration is mandatory to progress the field.

Targeting the PI3K/AKT/mTOR pathway in biliary tract cancers: A review of current evidences and future perspectives

Biliary tract cancers (BTCs) are a group of invasive neoplasms, with increasing incidence and dismal prognosis. In advanced disease, the standard of care is represented by first-line chemotherapy with cisplatin and gemcitabine. In subsequent lines, no clear recommendations are currently available, highlighting the need for novel therapeutic approaches. The PI3K/AKT/mTOR pathway is a core regulator of cell metabolism, growth and survival, and is involved in BTCs carcinogenesis and progression. Mutations, gene copy number alterations and aberrant protein phosphorylation of PI3K, AKT, mTOR and PTEN have been thoroughly described in BTCs and correlate with poor survival outcomes. Several pre-clinical evidences state the efficacy of PI3K/AKT/mTOR pathway inhibitors in BTCs, both in vitro and in vivo. In the clinical setting, initial studies with rapamycin analogs have shown interesting activity with an acceptable toxicity profile. Novel strategies evaluating AKT and PI3K inhibitors have risen serious safety concerns, pointing out the need for improved patient selection and increased target specificity for the clinical development of these agents, both alone and in combination with chemotherapy. This review extensively describes the role of the PI3K/AKT/mTOR pathway in BTCs and examines the rationale of its targeting in these tumors, with particular focus on clinical activity, toxicities and perspectives on further development of PI3K/AKT/mTOR pathway inhibitors.

Targeting phosphoinositide-3-kinase pathway in biliary tract cancers: A remedial route?

Biliary tract cancers (BTC) are aggressive tumours with a low survival rate. At the advent of the genomic era, various genetic mutations in cell signalling pathways have been incriminated in carcinogenesis. Genomic analysis studies have connected main components of the phosphoinositide-3-kinase (PI3K) signalling pathway to BTC. PI3K pathway playing a central role in cell signalling and being deregulated in various tumours has been studied as a target for chemotherapy. Novel compounds have also been identified in preclinical trials that specifically target the PI3K pathway in BTCs, but these studies have not accelerated to clinical use. These novel compounds can be examined in upcoming studies to validate them as potential therapeutic agents, as further research is required to combat the growing need for adjuvant chemotherapy to successfully battle this tumour type. Furthermore, these molecules could also be used along with gemcitabine, cisplatin and 5-fluorouracil to improve sensitivity of the tumour tissue to chemotherapy. This review focuses on the basics of PI3K signalling, genetic alterations of this pathway in BTCs and current advancement in targeting this pathway in BTCs. It emphasizes the need for gene-based drug screening in BTC. It may reveal various novel targets and drugs for amelioration of survival in patients with BTC and serve as a stepping stone for further research.

RETRACTED: EMP3, which is regulated by miR-663a, suppresses gallbladder cancer progression via interference with the MAPK/ERK pathway

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor. Following the publication of the above article, the Editor was notified that images were duplicated in the migration and invasion experiments in Figures 3A, 6C, 7D and 8D: https://pubpeer.com/publications/76E82FD26E33503D7CCAC01C324AFA. The Editor has taken the decision to retract the paper as it is no longer acceptable in its current form

Tumor suppressor LKB1 inhibits the progression of gallbladder carcinoma and predicts the prognosis of patients with this malignancy

Gallbladder carcinoma (GBC) represents the most common fatal tumors of the biliary tract. The 3-year or 5-year survival rate for patients with this disease are 30 and 5%, respectively. Liver kinase B1 (LKB1), a primary upstream kinase of adenosine monophosphate-activated protein kinase (AMPK) necessary for maintaining cell metabolism and energy homeostasis, has been found to be an important tumor suppressor gene in recent years, and its inactivation has also found to be closely associated with tumor growth, metastasis and cancer stem cell (CSC) proliferation. Nevertheless, the function of LKB1 in GBC remains unclear. In this study, we found that the expression of LKB1 in GBC tissues was decreased compared with that in non-cancerous tissues. LKB1 overexpression suppressed the proliferation, metastasis and expansion of GBC CSCs. Mechanically, LKB1 suppressed GBC cell progression via the JAK/signal transducer and activator of transcription 3 (STAT3) pathway. The use of the JAK2 inhibitor, AZD‑1480, attenuated the suppressive effects of LKB1 overexpression on the growth, metastasis and self-renewal ability of the GBC cells, which further demonstrated that JAK/STAT3 was involved in the LKB1-induced suppression of GBC cell growth, metastasis and self-renewal ability. More importantly, the decreased expression of LKB1 was a predictor of a poor prognosis of patients with GBC. On the whole, our data indicate that LKB1 inhibits GBC cell growth, metastasis and self-renewal ability by disrupting JAK/STAT3 signaling, and may thus prove to be a novel prognostic biomarker for patients with GBC.

Ring finger protein 125, as a potential highly aggressive and unfavorable prognostic biomarker, promotes the invasion and metastasis of human gallbladder cancers via activating the TGF- β1-SMAD3-ID1 signaling pathway

Human gallbladder cancer (GBC) is a lethal aggressive malignant neoplasm. Identification of potential molecular biomarkers and development of targeted therapeutics for GBC patients is very necessary. In this study, we firstly investigated the correlation between ring finger protein 125 (RNF125) expression and the metastasis and prognosis of GBC, and the underlying molecular mechanism. RNF125 expression in a cohort of GBC tissues was examined; its correlation with clinicopathological and prognostic factors of GBC patients was analyzed. Moreover, the metastasis-related difference expressed genes in highly and lowly aggressive GBC cell lines were identified; and the influence of RNF125 knockdown on the metastatic phenotypes and characteristic EMT markers in highly aggressive GBC NOZ cells was detected. Furthermore, the underlying molecular mechanism of RNF125 effect was explored. The results showed that RNF125 was highly expressed in GBC tissues and related with aggressive characteristics such as Nevin stage (P = 0.041) etc. and unfavorable prognosis of GBC patients (P = 0.023, log-rank test). And, RNF125 was proved to a positive metastasis-related gene in vitro. RNF125 knockdown inhibited the invasion and migration, enhanced the adhesion, upregulated E-cadherin and β-catenin expression, and downregulated vimentin and N-cadherin expression (all P < 0.001) of NOZ cells in vitro. RNF125 promoting effect on GBC tumor progression was identified to relate with the activation of TGF-β1-SMAD3-ID1 signaling pathway. These findings firstly confirm that high RNF125 expression is related with aggressive characteristics and unfavorable prognosis of GBC patients; RNF125 promotes the invasion and metastasis of human GBCs via activating the TGF-β1-SMAD3-ID1 signaling pathway.

Phase I dose-escalation study of copanlisib in combination with gemcitabine or cisplatin plus gemcitabine in patients with advanced cancer

Background:

Copanlisib is a pan-class I phosphatidylinositol 3-kinase (PI3K) inhibitor with predominant PI3K-α/δ activity that has demonstrated clinical activity and manageable safety when administered as monotherapy in a phase II study. Combination therapy may overcome compensatory signalling that could occur with PI3K pathway inhibition, resulting in enhanced inhibitory activity, and preclinical studies of copanlisib with gemcitabine have demonstrated potent anti-tumour activity in vivo.

Methods:

A phase I, open-label, dose-escalation study to evaluate the safety, tolerability and recommended phase II dose (RP2D) of copanlisib with gemcitabine or with cisplatin plus gemcitabine (CisGem) in patients with advanced malignancies, including an expansion cohort in patients with biliary tract cancer (BTC) at the RP2D of copanlisib plus CisGem. Copanlisib and gemcitabine were administered on days 1, 8 and 15 of a 28-day cycle; maximum tolerated dose (MTD) and RP2D of copanlisib were determined. Copanlisib plus CisGem was administered on days 1 and 8 of a 21-day cycle; pharmacokinetics and biomarkers were assessed.

Results:

Fifty patients received treatment as follows: dose-escalation cohorts, n=16; copanlisib plus CisGem cohort, n=14; and BTC expansion cohort, n=20. Copanlisib 0.8 mg kg⁻¹ plus gemcitabine was the MTD and RP2D for both combinations. Common treatment-emergent adverse events included nausea (86%), hyperglycaemia (80%) and decreased platelet count (80%). Copanlisib exposure displayed a dose-proportional increase. No differences were observed upon co-administration of CisGem. Response rates were as follows: copanlisib plus gemcitabine, 6.3% (one partial response in a patient with peritoneal carcinoma); copanlisib plus CisGem, 12% (one complete response and three partial responses all in patients with BTC (response rate 17.4% in patients with BTC)). Mutations were detected in PIK3CA (1 out of 43), KRAS (10 out of 43) and BRAF (2 out of 22), with phosphate and tensin homologue protein loss in 41% (12 out of 29).

Conclusions:

Copanlisib plus CisGem demonstrated a manageable safety profile, favourable pharmacokinetics, and potentially promising clinical response.

Genotyping and mRNA profiling reveal actionable molecular targets in biliary tract cancers

Biliary tract cancer (BTC) represents a heterogeneous disease with dismal outcome. Herein, we examined genotype and angiogenesis features in BTC. We applied genotyping (Sanger, qPCR, 101-gene panel NGS), mRNA relative quantification methods, and β-catenin immunohistochemistry in 84 FFPE BTC (55 gallbladder [GBC], 14 intrahepatic [ICC], 15 extrahepatic [ECC] carcinomas). We identified 541 mutations in 68 (81%) tumors. Top mutated genes were CTNNB1 (36%); PTEN (33%); TP53 (31%); PIK3R1 (29%); PIK3CA (13%); BRCA2 and KRAS (12%); BRCA1 (11%). Six GBCs were hypermutated [hm] displaying a distinct mutational pattern. Mutations in TP53 and PI3K, Wnt and RAS components were prevalent among non-hypermutated tumors. All hmGBCs carried mutations in BRCA2 and other homologous recombination repair (HRR) genes, in PD1, but not in CTNNB1 and KRAS. None of the pathogenic BRCA2 p.D2723G and BRCA1 p.Q563* and c.5266dupC was present at frequencies expected for germline mutations. We observed copy gains (>6 copies) in EGFR (9% of informative tumors), PRKAR1A (7%), PIK3CA (6%), ERBB2 (5%) and MET (4%). TP53 mutations were prevalent in GBC (P<0.001) and PRKAR1A copy gains in ICC (P=0.007). PTEN was frequently co-mutated with CTNNB1 (P<0.001). Unrelated to CTNNB1 mutations, nuclear β-catenin was detected in 45% of tumors, among them in 5/6 hmGBC. We observed strong mRNA expression correlation of the two neuropilins (NRP1 and NRP2) with each other (Spearman's rho 0.59) and with the endothelin receptor (NRP2 rho 0.66; NRP2 rho 0.51), and between VEGFA and its receptors (FLT1 rho 0.49; KDR rho 0.45). All PIK3CA mutated tumors expressed endothelin 1 mRNA (P=0.010). Most tumors expressing nuclear β-catenin were negative for VEGFC (P=0.009) and FLT4 (P=0.002) mRNA expression. In conclusion, we confirmed the presence of known genomic aberrations in BTC and different genotypes between BTC subsets. Novel findings are the coexistence of PI3K and WNT pathway gene alterations in BTC, their association with angiogenesis, and the hypermutated GBCs with HRR gene mutations, all of which may be considered for new treatment options in this difficult to treat disease.

Epithelial-to-mesenchymal transition in gallbladder cancer: from clinical evidence to cellular regulatory networks

Gallbladder cancer (GBC), with late diagnosis, rapid disease progression and early metastasis, is a highly aggressive malignant tumor found worldwide. Patients with GBC have poor survival, low curative resection rates and early recurrence. For such a lethal tumor, uncovering the mechanisms and exploring new strategies to prevent tumor progression and metastasis are critically important. Epithelial-to-mesenchymal transition (EMT) has a prominent role in the early steps of tumor progression and metastasis by initiating polarized epithelial cell transition into motile mesenchymal cells. Accumulating evidence suggests that EMT can be modulated by the cooperation of multiple mechanisms affecting common targets. Signaling pathways, transcriptional and post-transcriptional regulation and epigenetic alterations are involved in the stepwise EMT regulatory network in GBC. Loss of epithelial markers, acquisition of mesenchymal markers and dysregulation of EMT-inducing transcription factors (EMT-TFs) have been observed and are associated with the clinicopathology and prognosis of GBC patients. Therefore, EMT may be a detectable and predictable event for predicting GBC progression and metastasis in the clinic. In this review, we will provide an overview of EMT from the clinical evidence to cellular regulatory networks that have been studied thus far in clinical and basic GBC studies.

Mutational frequency of KRAS, NRAS, IDH2, PIK3CA, and EGFR in North Indian gallbladder cancer patients

BACKGROUND

Gallbladder cancer (GBC) has a peculiar geographical distinction, with a high prevalence seen in North India and Chile. There are various aetiopathogenetic mechanisms of GBC causation; one of them is a series of pathogenic mutations, which is responsible for the malignant transformation of gallbladder epithelium. Therefore, the present study aimed to find out cancer-specific hot spot mutations in five major cancer-related genes KRAS exon1 &2, NRAS exon1, IDH2 exon, PIK3CA exon 20, IDH2 exon 4 and EGFR exon 20 in North Indian GBC patients and their association with clinicopathological variables.

MATERIAL AND METHODS

This study included 34 histopathologically confirmed GBC cases. The clinical material consisted of formalin-fixed paraffin-embedded (FFPE) blocks of the patients. DNA isolation was done from FFPE tissue. DNA sequencing was performed by the capillary electrophoresis method. The chi-square (χ²) test was used to test for a statistically significant relationship between two categorical study variables.

RESULTS

The overall incidence of somatic mutations in KRAS exon 1&2, NRAS exon1, IDH2 exon4, PIK3CA exon20, and EGFR exon 20 in Indian GBC patients was found in 8/34 (23.5%), 3/34 (8.8%), 4/34 (11.7%), 7/34 (20.6%), 7/34 (20.6%), respectively. KRAS exon 1 and two mutations were found to be significantly associated with advanced stage GBC patients.

CONCLUSION

KRAS, PIK3CA, and EGFR were found to be the most frequently mutated genes among the five tested in this study.

EIF3D promotes gallbladder cancer development by stabilizing GRK2 kinase and activating PI3K-AKT signaling pathway

Recent evidence suggests that dysregulated eIF3d expression may be critical in various genetic disorders as well as cancer. In this study, we observed that EIF3d levels increased in gallbladder cancer (GBC) samples compared with non-tumor tissue. High eIF3d levels were associated with advanced tumor stage and metastasis and were correlated with poor prognosis in 92 patients with GBC. Depletion of EIF3d in GBC cell lines inhibited cell proliferation, colony formation and metastasis and induced apoptosis and cell cycle arrest in vitro and in vivo. In contrast, ectopic expression of eIF3d had the opposite effects. Moreover, in this study, we revealed that a novel non-translational factor function of eIF3d mediated its protumoral effects. In details, eIF3d stabilizes GRK2 protein by blocking ubiquitin-mediated degradation, consequently activates PI3K/Akt signaling, and promotes GBC cell proliferation and migration. In conclusion, eIF3d promotes GBC progression mainly via eIF3d-GRK2-AKT axis and it may be used as a prognostic factor. The therapeutic targeting of eIF3d-GRK2 axis may be a potential treatment approach for GBC.

Chloride intracellular channel 1 regulates the antineoplastic effects of metformin in gallbladder cancer cells

Metformin is the most commonly used drug for type 2 diabetes and has potential benefit in treating and preventing cancer. Previous studies indicated that membrane proteins can affect the antineoplastic effects of metformin and may be crucial in the field of cancer research. However, the antineoplastic effects of metformin and its mechanism in gallbladder cancer (GBC) remain largely unknown. In this study, the effects of metformin on GBC cell proliferation and viability were evaluated using the Cell Counting Kit‐8 (CCK‐8) assay and an apoptosis assay. Western blotting was performed to investigate related signaling pathways. Of note, inhibition, knockdown and upregulation of the membrane protein Chloride intracellular channel 1 (CLIC1) can affect GBC resistance in the presence of metformin. Our data demonstrated that metformin apparently inhibits the proliferation and viability of GBC cells. Metformin promoted cell apoptosis and increased the number of early apoptotic cells. We found that metformin can exert growth‐suppressive effects on these cell lines via inhibition of p‐Akt activity and the Bcl‐2 family. Notably, either dysfunction or downregulation of CLIC1 can partially decrease the antineoplastic effects of metformin while upregulation of CLIC1 can increase drug sensitivity. Our findings provide experimental evidence for using metformin as an antitumor treatment for gallbladder carcinoma.