Search

Despite significant improvement in therapeutic development in the past decades, breast cancer remains a formidable cause of death for women worldwide. The hormone positive subtype (HR(+)) (also known as luminal type) is the most prevalant category of breast cancer, comprising ~70% of patients. The clinical success of the three CDK4/6 inhibitors palbociclib, ribociclib, and abemaciclib has revolutionized the treatment of choice for metastatic HR(+) breast cancer. Accumulating evidence demonstrate that the properties of CDK4/6 inhibitors extend beyond inhibition of the cell cycle, including modulation of immune function, sensitizing PI3K inhibitors, metabolism reprogramming, kinome rewiring, modulation of the proteosome, and many others. The ubiquitin-proteasome pathway (UPP) is a crucial cellular proteolytic system that maintains the homeostasis and turnover of proteins.We performed transcriptional profiling of the HR(+) breast cancer cell lines MCF7 and T47D treated with Palbociclib. Differential expressed genes were analyzed for novel pathways enriched. The results were further validated with biochemical assays and with real world clinical database cohorts.We uncovered a novel mechanism that demonstrate the CDK4/6 inhibitors suppress the expression of three ubiquitin conjugating enzymes UBE2C, UBE2S, UBE2T. Further validation in the HR(+) cell lines show that Palbociclib and ribociclib decrease UBE2C at both the mRNA and protein level, but this phenomenon was not shared with abemaciclib. These three E2 enzymes modulate several E3 ubiquitin ligases, including the APC/C complex which plays a role in G1/S progression. We further demonstrate the UBE2C/UBE2T expression levels are associated with breast cancer survival, and HR(+) breast cancer cells demonstrate dependence on the UBE2C.Our study suggests a novel link between CDK4/6 inhibitor and UPP pathway, adding to the potential mechanisms of their clinical efficacy in cancer.

Breast cancer is one of the leading causes of cancer death in women, and although treatment outcome has substantially improved in the past decades, advanced or metastatic breast cancers still carry a poor prognosis. Gene amplification is one of the frequent genetic alterations in cancer, and oncogene amplification may be associated with cancer aggressiveness and oncogenicity. Targeting amplified genes such as HER2 has vastly improved disease outcome and survival, and anti-HER2 therapeutics have revolutionized the standard of care in HER2 breast cancer. Besides currently known druggable gene amplifications including ERBB2 and FGFR2, other frequently amplified genes are relatively less well known for function and clinical significance. By querying 4 large databases from TCGA and AACR-Genie, from a total of 11,890 patients with invasive ductal breast carcinoma, we discover IKZF3, CCND1, ERBB2 to be consistently amplified across different cohorts. We further identify IKZF3 as a frequently amplified gene in breast cancer with a prevalence of 12–15% amplification rate. Interestingly, IKZF3 amplification is frequently co-amplified with ERBB2/HER2, and is also associated with worse prognosis compared to IKZF3 non-amplified cancers. Analysis of HER2 breast cancer patients treated with trastuzumab revealed decrease in both ERBB2/HER2 and IKZF3 expression. Further investigation using the DepMap for gene dependency by genome wide CRISPR screening revealed dependence on IKZF3 in HER2 breast cancer cell lines. Our study utilized an integrative analysis of large scale patient genomics, transcriptomics and clinical data to reveal IKZF3 as a frequently amplified gene, and suggest a potential role of IKZF3 as a druggable target for HER2 breast cancer.

Hormone positive (HR+) breast cancer is the most common subtype in this population. The current standard of care in advanced HR+ breast cancer includes endocrine therapy (tamoxifen, aromatase inhibitors, etc) and CDK4/6 inhibitors. CDK4/6 inhibitors significantly prolong survival and is now the general accepted choice of drug in first line. Despite the enormous clinical benefit, there remains a substantial portion of patients who ultimately develop resistance against CDK4/6 inhibitors. Many mechanisms have been proposed for CDK4/6 inhibitor resistant, including upregulation of CDK4, CDK6, Cyclin E, and others. Recently studies have linked the hippo pathway to CDK6 upregulation and resulting in CDK4/6 inhibitor resistance. We have set up a kinase library screen for kinase inhibitors that downregulate CDK6 amplification and further assess for reversal of resistance. We discovered staurosporine and the PI3K inhibitor PIK-75 as small molecules that potently downregulate CDK6 expression in breast cancer cells. We further confirmed that these compounds reverse the resistance towards CDK4/6 inhibitors in CDK6 amplification cells. By kinase profiling combined with a small hairpin RNA (shRNA) screen, we discovered the mechanisms that resulted in CDK6 downregulation and modulation of the hippo pathway to reverse the CDK4/6 inhibitor resistance. Our discovery has implications for therapeutic development in this group of patients posing a huge unmet need. Citation Format: Chung-Jen Yu, Yong-Ji Zhuang, Ting-Yi Lin, Ta-Chung Chao, Chun-Yu Liu, Ling-Ming Tseng, Jiun-I Lai. Discovery of mechanisms that modulate the hippo pathway and CDK6 expression in CDK4/6 inhibitor resistant breast cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5975.

Breast cancer is one of the most common cancers and a leading cause of death in women worldwide. Among these subtypes, triple negative breast cancer (TNBC) has the worst prognosis, with a dismal outcome especially in metastatic disease. Metastatic TNBC treated with conventional chemotherapy has a median overall survival (OS) of ~ 18 months. The addition of checkpoint inhibitors extend the median OS to more than 2 years in PD-L1 positive patients, but ultimately most patients succumb to the disease. Currently TNBC still poses as a clinical unmet need, and further understanding of the cancer biology may shed light in improving therapeutics against this deadly disease. Apoptosis, or programmed cell death, is a crucial function for cell homeostasis. The ability to evade or circumvent apoptosis is an important hallmark of cancer cells. X-linked ectodermal dysplasia receptor (XEDAR), a cell membrane receptor that binds to the pro-apoptotic ligand EDA-A2, is a member of the TNF receptor family and has been reported to be downregulated in breast cancer cells. XEDAR has been shown to induce downstream apoptosis by binding to EDA-A2, by a mechanism similar to extrinsic apoptotic pathway. By interrogating clinical databases and cross comparison using TCGA, CCLE, and other breast cancer datasets, we discover XEDAR as substantially downregulated in TNBC. Transcription profile analysis between different XEDAR expressing profiles uncovered novel pathways that could be potentially targeted for TNBC treatment. RNA-seq profiling in XEDAR overexpressing TNBC cells were cross compared with aforementioned discovered pathways. Vulnerable pathways including angiogenesis were discovered as possible therapeutic targets. As a proof of concept, we combined angiogenesis inhibitors with EDA-A2 ligand treatment in XEDAR overexpression TNBC cells and observed synergistic effects for combination. Our study uncover XEDAR as a potential target for further treatment in TNBC, which remains to be further validated in preclinical and clinical studies. Citation Format: Chih-Yi Lin, Chung-Jen Yu, Chih-Yang Wang, Kai-Jun Liu, Jiun-I Lai. Characterization the mechanistic role of the proapoptotic receptor XEDAR and its therapeutic potential in TNBC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5651.

Objectives ABIGAIL, a phase II, randomized, open-label, multicenter study evaluated the correlation between biomarkers and best overall response (BOR) to bevacizumab with chemotherapy in patients with advanced or recurrent non-small-cell lung cancer (NSCLC). Exploratory analyses of vascular endothelial growth factor (VEGF) clinical genotyping data are presented. Materials and methods A total of 303 patients with NSCLC were randomized to receive bevacizumab 7.5 mg/kg or 15 mg/kg until progression or unacceptable toxicity (plus six cycles of chemotherapy). Patients provided blood samples for biomarker analysis. Exploratory analyses were conducted to assess whether genetic variants in VEGF-A or VEGFR-1/-2 act as efficacy or safety biomarkers. Single nucleotide polymorphisms (SNPs) were determined using individual genotyping assays. DNA analysis for 12 SNPs across three genes is reported: VEGF-A (five SNPs), VEGFR-1 (three SNPs), and VEGFR-2 (four SNPs). Results VEGF-A: c.+405/c.−634 (CG), VEGF-A: c.−460 >C; c−1498 >C (CT), and VEGF-A: c.−2578 C>A were associated with >50% higher odds of responding to treatment. VEGFR-1: rs9554316 (GT) was associated with >30% higher risk of progression and >40% higher risk of death. VEGF-A: c.+936 C>T was associated with higher incidence of hypertension. Conclusions Four genetic variants of VEGF-A and VEGFR-1 were associated with bevacizumab treatment outcome. Three variants in VEGF-A were associated with increased BOR, one variant in VEGFR-1 was associated with worse progression-free survival/overall survival. These associations were not statistically significant after correction for multiple testing. No genetic variant was associated with significantly higher risk of hypertension. Replication in additional studies may provide insight into the use of these variants to predict response to bevacizumab.

BackgroundThe incidence of candidemia varied between hospitals and different study periods. Few, if any, studies provide the reasons. This hospital-based population study aimed to describe and compare the patient population hospitalized in 2002 and 2010 and determine the disease-specific incidences of candidemia and evaluate the impact of time to initiate antifungal therapy on 30-day mortality.Patients and methodsAll patients hospitalized at a 2300-bed teaching hospital in Taiwan in 2002 and 2010 were analyzed for the distribution of age, sex, and type of underlying diseases (maximum of six diagnoses). All patients with blood isolates that were collected in 2002 and 2010 and yielded Candida species were included for analysis of the demographic and clinical characteristics, distribution of Candida species, length of hospital stay before candidemia, stay in the intensive care units at onset of candidemia, time of initiating systemic antifungal agent, antifungal regimen, and 30-day crude mortality.ResultsIn 2010, the hospitalized patients were older (p

Summary Background Afatinib is an irreversible ErbB-family blocker with preclinical activity in non-small-cell lung cancer (NSCLC) with EGFR mutations. We aimed to assess the efficacy of afatinib in patients with lung adenocarcinoma and EGFR mutations. Methods In this phase 2 study, we enrolled patients from 30 centres in Taiwan and the USA with lung adenocarcinoma (stage IIIb with pleural effusion or stage IV) with EGFR mutations, who had no more than one previous chemotherapy regimen for advanced disease, an Eastern Cooperative Oncology Group performance status of 0–2, and no previous treatment with EGFR tyrosine-kinase inhibitors. We tested two afatinib starting doses: 50 mg daily and subsequently 40 mg daily, introduced to establish whether tolerability could be improved with retention of anti-tumour activity. The primary endpoint was the proportion of patients with a confirmed objective response (complete response or partial response), on the basis of Response Evaluation Criteria in Solid Tumors 1.0 (independent review). This study is registered with ClinicalTrials.gov, number NCT00525148. Findings 129 patients were treated with afatinib, 99 with a starting dose of 50 mg and 30 with a starting dose of 40 mg. 79 (61%) of 129 patients had an objective response (two complete responses, 77 partial responses). 70 (66%) of the 106 patients with the two common activating EGFR mutations (deletion 19 or L858R) had an objective response, as did nine (39%) of 23 patients with less common mutations. Similar proportions of patients had an objective response when analysed by starting dose (18 [60%] of 30 patients at 40 mg vs 61 [62%] of 99 patients at 50 mg). Of the two most common adverse events (diarrhoea and rash or acne), grade 3 events were more common in patients receiving a 50 mg starting dose (22 [22%] of 99 patients for diarrhoea and 28 [28%] of 99 patients for rash or acne) than they were in those receiving a 40 mg starting dose (two [7%] of 30 patients for both diarrhoea and rash or acne); possibly treatment-related serious adverse events were also less common in patients receiving a 40 mg starting dose (two of 30 patients vs 14 of 99 patients). We recorded one possibly drug-related death (interstitial lung disease). Interpretation Afatinib shows activity in the treatment of patients with advanced lung adenocarcinoma with EGFR mutations, especially in patients with deletion 19 or L858R mutations. The efficacy of afatinib 40 mg should be compared with chemotherapy or other EGFR tyrosine-kinase inhibitors in EGFR-mutation-positive NSCLC. Funding Boehringer Ingelheim Inc.

For the application of In-49Sn solder in bonding recycled-sputtering targets to Cu back plates, the intermetallic compounds formed at the In-49Sn/Cu interface are investigated. Scanning electron microscopy (SEM) observations show that the interfacial intermetallics consist of a planar layer preceded by an elongated scalloped structure. Electron-probe microanalyzer analyses indicate that the chemical compositions of the planar layer and the scalloped structure are Cu74.8In12.2Sn13.0 and Cu56.2In20.1Sn23.7, respectively, which correspond to the ɛ-Cu3(In,Sn) and η-Cu6(In,Sn)5 phases. Kinetics analyses show that the growth of both intermetallic compounds is diffusion controlled. The activation energies for the growth of η- and ɛ-intermetallics are calculated to be 28.9 kJ/mol and 186.1 kJ/mol. Furthermore, the formation mechanism of intermetallic compounds during the In-49Sn/Cu soldering reaction is clarified by marking the original interface with a Ta-thin film. Wetting tests are also performed, which reveal that the contact angles of liquid In-49Sn drops on Cu substrates decline to an equilibrium value of 25°C.

The interfacial reactions between liquid In and Cu substrates at temperatures ranging from 175°C to 400°C are investigated for the applications in bonding recycled sputtering targets to their backing plates. Experimental results show that a scallop-shaped Cu16In9 intermetallic compound is found at the Cu/In interface after solder reactions at temperatures above 300°C. A double-layer structure of intermetaltic compounds containing scallop-shaped Cu11In9 and continuous CuIn is observed after the Cu/In interfacial reaction at temperatures below 300°C. The growth of all these intermetallic compounds follows the parabolic law, which implies that the growth is diffusion-controlled. The activation energies for the growth of Cu16In9, Cu11In9, and CuIn intermetallic compounds calculated from the Arrhenius plot of growth reaction constants are 59.5, 16.9, and 23.5 kJ/mole, respectively.

1,3-Propanediol (1,3-PD) can be used for the industrial synthesis of a variety of compounds, including polyesters, polyethers, and polyurethanes. 1,3-PD is generated from petrochemical and microbial sources. 1,3-Propanediol is a typical product of glycerol fermentation, while acetate, lactate, 2,3-butanediol, and ethanol also accumulate during the process. Substrate and product inhibition limit the final concentration of 1,3-propanediol in the fermentation broth. It is impossible to increase the yield of 1,3-propanediol by using the traditional whole-cell fermentation process. In this study, dhaD and dhaK, the genes for glycerol dehydrogenase and dihydroxyacetone kinase, respectively, were inactivated by homologous recombination in Klebsiella pneumoniae. The dhaD/dhaK double mutant (designated TC100), selected from 5,000 single or double cross homologous recombination mutants, was confirmed as a double cross by using polymerase chain reaction. Analysis of the cell-free supernatant with high-performance liquid chromatography revealed elimination of lactate and 2,3-butanediol, as well as ethanol accumulation in TC100, compared with the wild-type strain. Furthermore, 1,3-propanediol productivity was increased in the TC100 strain expressing glycerol dehydratase and 1,3-PDO dehydrogenase regulated by the arabinose P(BAD) promoter. The genetic engineering and medium formulation approaches used here should aid in the separation of 1,3-propanediol from lactate, 2,3-butanediol, and ethanol and lead to increased production of 1,3-propanediol in Klebsiella pneumoniae.