IGF-1R as an anti-cancer target—trials and tribulations

Type I insulin-like growth factor receptor (IGF-1R) has long been recognized for its role in tumorigenesis and growth, but only recently have the tools for targeting the IGF pathway become available. More than 10 IGF/IGF-1R inhibitors have entered clinical trials, and these belong to three main classes: (1) monoclonal antibodies against IGF-1R, (2) monoclonal antibodies against IGF-1R ligands (IGF-1 and IGF- 2), and (3) IGF-1R tyrosine kinase inhibitors. These IGF-1R-targeting agents share common effects on IGF-1R signaling but differ in mechanisms of action, spectrum of target inhibition, and pharmacological features. Clinical activity of IGF-1R inhibitors has been demonstrated with sustained responses in a small number of patients with select tumor types, such as Ewing sarcoma and thymoma. However, many large clinical trials involving patients with adult tumors, including non-small cell lung cancer, breast cancer, and pancreatic cancer, failed to show clinical benefit in the overall patient population. Possible reasons for failure include the complexity of the IGF-1R/insulin receptor system and parallel growth and survival pathways, as well as a lack of patient selection markers. While IGF-1R remains a valid target for selected tumor types, identification of predictive markers and rational combinations will be critical to success in future development.     

SFRP1 reduction results in an increased sensitivity to TGF-β signaling

Background  

Transforming growth factor (TGF)-β plays a dual role during mammary gland development and tumorigenesis and has been shown to stimulate epithelial-mesenchymal transition (EMT) as well as cellular migration. The Wnt/β-catenin pathway is also implicated in EMT and inappropriate activation of the Wnt/β-catenin signaling pathway leads to the development of several human cancers, including breast cancer. Secreted frizzled-related protein 1 (SFRP1) antagonizes this pathway and loss of SFRP1 expression is frequently observed in breast tumors and breast cancer cell lines. We previously showed that when SFRP1 is knocked down in immortalized non-malignant mammary epithelial cells, the cells (TERT-siSFRP1) acquire characteristics associated with breast tumor initiating cells. The phenotypic and genotypic changes that occur in response to SFRP1 loss are consistent with EMT, including a substantial increase in the expression of ZEB2. Considering that ZEB2 has been shown to interact with mediators of TGF-β signaling, we sought to determine whether TGF-β signaling is altered in TERT-siSFRP1 cells.     

New Delhi metallo-β-lactamase (NDM-1): an update

New Delhi metallo-β-lactamase (NDM-1) is a novel broad spectrum carbapenemase with ability to inactivate all β-lactams except aztreonam. However, most of the NDM-1-producers also produce aztreonam hydrolysing-β-lactamases thereby making these pathogens absolutely resistant to all β-lactams. The bla(NDM-1) gene encodes a 27.5 kDa protein of 269 amino acids. It shares very little identity with other metallo-β-lactamases. Maximum identity has been observed to VIM-1/VIM-2 (32.4%). This mini-review is an update of the scientific literature for the said enzyme. Following the recommendation of David livermore, we further propose to combine "aztreonam" and "inhibitor of the most frequently encountered aztreonam hydrolysing-β-lactamases in a given setting" as a possible strategy against NDM-1-producers. The inhibitor should be 'versatile' as well, i.e. it should have the ability to inhibit most of the variants of aztreonam hydrolysing-β-lactamases prevalent in the concerned setting. We strongly recommend surveillance studies using aztreonam/NXL-104-combination against NDM-1-producing pathogens in different geographical regions across the globe.     

Activated macrophages promote invasion by early colorectal cancer via an interleukin 1β-serum amyloid A1 axis

Submucosal invasion and lymph node metastasis are important issues affecting treatment options for early colorectal cancer (CRC). In this study, we aimed to unravel the molecular mechanism underlying the invasiveness of early CRCs. We performed RNA-sequencing (RNA-seq) with poorly differentiated components (PORs) and their normal counterparts isolated from T1 CRC tissues and detected significant upregulation of serum amyloid A1 (SAA1) in PORs. Immunohistochemical analysis revealed that SAA1 was specifically expressed in PORs at the invasive front of T1b CRCs. Upregulation of SAA1 in CRC cells promoted cell migration and invasion. Coculture experiments using CRC cell lines and THP-1 cells suggested that interleukin 1β (IL-1β) produced by macrophages induces SAA1 expression in CRC cells. Induction of SAA1 and promotion of CRC cell migration and invasion by macrophages were inhibited by blocking IL-1β. These findings were supported by immunohistochemical analysis of primary T1 CRCs showing accumulation of M1-like/M2-like macrophages at SAA1-positive invasive front regions. Moreover, SAA1 produced by CRC cells stimulated upregulation of matrix metalloproteinase-9 in macrophages. Our data suggest that tumor-associated macrophages at the invasive front of early CRCs promote cancer cell migration and invasion through induction of SAA1 and that SAA1 may be a predictive biomarker and a useful therapeutic target.     

Tumour infiltration depth ≥4 mm is an indication for an elective neck dissection in pT1cN0 oral squamous cell carcinoma

Patients with pT1cN0 oral squamous cell carcinomas (OSCC) are generally not treated with a neck dissection (ND). However, in 25% of cN0 patients, nodal metastases become apparent during follow-up. Infiltration depth of the primary tumour has been consistently associated with the presence of nodal metastasis, but proposed cut-off depths for performing a ND vary considerably. The aim of this study was to explore the infiltration depth as predictor for the nodal status and to recommend a cut-off depth for performing a ND. From our database of 351 primary oral carcinomas, we selected all pT1-2 tumours (n=246). Infiltration depth was measured in 212 cases. Neck status was determined by histopathological examination of the dissection specimen, or by at least two years of follow-up. Mean infiltration depth was 5.49 mm (95% CI: 4.86-6.12) in the N0 and 8.40 mm (95% CI: 7.38-9.43) in the N+ group (p<0.001). cN status, lymphovascular invasion and infiltration depth were the only independent predictors for nodal status in multiple logistic regression. ROC-analysis on pT1cN0 tumours resulted in an optimal cut-off for the prediction of the nodal status at a depth of 4.59 mm. This cut-off identified a subgroup of patients at increased risk for nodal metastasis (OR=8.3) and with significantly shorter survival. Tumour infiltration depth is an independent predictor for nodal status in pT1-2 OSCC. In pT1cN0 tumours, a cut-off at 4.59 mm results in the best predictive value. We recommend an infiltration depth of ≥4 mm as an indication to perform a neck dissection in pT1cN0 OSCC.     

BRCA1 promoter hypermethylation and protein expression in ovarian carcinoma—an Indian study

Mounting evidences suggest that aberrant methylation of CpG islands is a major pathway leading to the inactivation of tumour suppressor genes and the development of cancer. The aim of the current study was to examine the prevalence of the promoter hypermethylation and protein expression of the BRCA1 gene in epithelial ovarian carcinoma (EOC) to understand the role of epigenetic silencing in ovarian carcinogenesis. We studied the promoter methylation of the BRCA1 gene by methylation-specific PCR in a cohort of 88 patients with EOC, 14 low malignant potential (LMP) tumours and 20 patients with benign tumours of the ovary. The expression of the BRCA1 protein by immunohistochemical analysis was carried out in a subset of 64 EOCs, 10 LMP tumours, 10 benign tumours and 5 normal ovarian tissues. The frequencies of methylation in EOCs and LMP tumours were 51.2 and 57 %, respectively, significantly higher (p?=?0.000 and p?=?0.001) in comparison to benign tumours and normal ovarian tissue where no methylation was seen. Expression of BRCA1 was significantly lower in EOCs (p?=?0.003). Lack of protein expression correlated with tumour grade and type. The methylation status correlated well with downregulation of BRCA1 expression. Our results clearly demonstrate that hypermethylation of BRCA1 promoter is a frequent event in ovarian cancer. These data support the hypothesis that BRCA1 promoter methylation plays an important role in the functional inactivation of BRCA1. Follow-up clinical data will reveal the impact of BRCA1 methylation on survival.     

Hypoxia-inducible factor 1α is closely linked to an aggressive phenotype in breast cancer

PURPOSE: The aim of this study is to clarify characteristics of invasive breast cancer with expression of Hypoxia-induced factor 1alpha (HIF-1alpha) which is induced by hypoxia and signal transduction of growth factors. EXPERIMENTAL DESIGN : We examined, by immunohistochemical analysis, the expression of HIF-1alpha in normal breast tissue, benign disorders and breast cancer. In invasive breast cancer, we investigated the correlation between expression of HIF-1alpha and clinicopathological and biological factors. We also studied the prognostic value of HIF-1alpha in breast cancer. RESULTS : HIF-1alpha was mainly detected in tumor cell nuclei. In the 171 cases of invasive breast cancer examined, nuclear HIF-1alpha expression was detected in 63 (36.8%) cases. Immunoreactive nuclear HIF-1alpha was correlated with tumor size (p = 0.0013), lymph node metastasis (p = 0.0005), tumor stage (p = 0.0031) and histological grade (p = 0.0074). Elevated HIF-1alpha levels was also associated with hormone receptor negativity (p = 0.0025), HER2 overexpression (p = 0.0053), high Ki67 labeling index (p = 0.0002), increased levels of VEGF (p < 0.0001), COX-2 overexpression (p = 0.0029) and increased nuclear p53 (p = 0.0048). In terms of the possible use of HIF-1alpha as a prognostic indicator, patients who had increased HIF-1alpha levels in their tumor showed shorter disease-free survival (DFS) (p < 0.0001) and overall survival (OS) (p = 0.0002) than those lacking HIF-1alpha in univariate analysis. In multivariate analysis of DFS and OS, HIF-1alpha was identified an independent prognostic factor. CONCLUSIONS: These findings suggest that HIF-1alpha was closely linked to an aggressive phenotype in breast cancer. It may be useful to study the expression of HIF-1alpha using immunohistochemical analysis for better understanding of the tumor characteristics of breast cancer.     

Hypoxia-inducible factor 1 alpha in high-risk breast cancer: an independent prognostic parameter?

Background  

Hypoxia-inducible factor 1 alpha (hif-1α) furnishes tumor cells with the means of adapting to stress parameters like tumor hypoxia and promotes critical steps in tumor progression and aggressiveness. We investigated the role of hif-1α expression in patients with node-positive breast cancer.     

Is ICI 182,780 an antiprogestin in addition to being an antiestrogen?

The pure antiestrogen ICI 182,780 has been shown to have antiprogestin activity in reporter gene constructs. Cell lines, naturally devoid of progesterone receptors (PR) were transfected with either the A or B forms of the human PR and a luciferase construct driven by a progesterone-response element (PRE). Because this system is an artificial one, our purpose was to determine whether these observations could be made in a human breast cancer cell line, naturally containing PR. We further evaluated the dose-response of ICI 182,780 and RU-486 (mifepristone) on PR and estrogen receptors (ER) in the presence of either progesterone, norgestrel or estradiol. These effects were measured using immunoassays for prostate-specific antigen (PSA) and human glandular kallikrein (hK2) and pS2. We found that ICI 182,780 blocked progesterone-stimulated PSA and hK2 production 100% at 10^–5 M, which decreased significantly by 10^–6 M. This inhibition did not occur when norgestrel was the progestin used. RU-486 showed 100% blockade for both progestins at all concentrations used. We concluded that the antiprogestin activity of ICI 182,780 exists for progesterone only. This weak antiprogestin activity may be unlikely to have significant clinical implications.     

Case Report of an Endodermal Sinus Vaginal Tumor in an Infant Girl

Case Report An female infant patient, aged 8 months old, suffered from irregular colporrhagia for a period of 1 month after which she was taken to our hospital on 30th April, 2003. A pelvic CT examination     

β1 integrin mediates an alternative survival pathway in breast cancer cells resistant to lapatinib

Introduction  

The overexpression of human epidermal growth factor receptor (HER)-2 in 20% of human breast cancers and its association with aggressive growth has led to widespread use of HER2-targeted therapies, such as trastuzumab (T) and lapatinib (L). Despite the success of these drugs, their efficacy is limited in patients whose tumors demonstrate de novo or acquired resistance to treatment. The β1 integrin resides on the membrane of the breast cancer cell, activating several elements of breast tumor progression including proliferation and survival.     

Truncating CDKN1A mutations: an insight into the biology of urinary tract carcinomas?

A recent in silico study by Arnoff and El-Deiry found that urothelial carcinomas of the bladder and upper tract as well as chromophobe renal cell carcinoma are more likely than other malignancies to harbor alterations in the CDKN1A gene, encoding for the cyclin-dependent kinase inhibitor p21^Waf1, a major target of p53 regulatory pathways. Most of these mutations were truncating and thus presumably resulting in loss of p21^Waf1 function. Herein, we discuss the prognostic and therapeutic implications of these findings.     

RAC1 GTPase plays an important role in γ-irradiation induced G2/M checkpoint activation

Introduction

In response to gamma-irradiation (IR)-induced double-strand DNA breaks, cells undergo cell-cycle arrest, allowing time for DNA repair before reentering the cell cycle. G₂/M checkpoint activation involves activation of ataxia telangiectasia mutated (ATM)/ATM- and rad3-related (ATR) kinases and inhibition of Cdc25 phosphatases, resulting in inhibition of Cdc2 kinase and subsequent G₂/M cell-cycle arrest. Previous studies from our laboratory showed that the G₂/M checkpoint activation after IR exposure of MCF-7 breast cancer cells is dependent on the activation of extracellular signal-regulated protein kinase 1 and 2 (ERK1/2) signaling. In the present studies, we investigated the role of Ras-related C3 botulinum toxin substrate 1 (Rac1) guanosine triphosphatase (GTPase) in IR-induced G₂/M checkpoint response and ERK1/2 activation, as well as in cell survival after IR.

Methods

With Rac1-specific inhibitor, dominant negative mutant Rac1 (N17Rac1) and specific small interfering RNA, the effect of Rac1 on IR-induced G₂/M checkpoint response and ERK1/2 activation was examined in human breast cancer cells. In addition, the effect of Rac1 on cell survival after irradiation was assessed by using Rac1-specific inhibitor.

Results

IR exposure of MCF-7 breast cancer cells was associated with a marked activation of Rac1 GTPase. Furthermore, inhibition of Rac1 by using specific inhibitor, dominant-negative Rac1 mutant, or specific siRNA resulted in attenuation of IR-induced G₂/M arrest and concomitant diminution of IR-induced activation of ATM, ATR, Chk1, and Chk2 kinases, as well as phosphorylation of Cdc2-Tyr15. Moreover, Rac1 inhibition or decreased Rac1 expression also abrogated IR-induced phosphorylation of mitogen-activated protein kinase kinase 1 and 2 (MEK1/2) and ERK1/2. Ultimately, inhibition of Rac1 markedly increased cellular sensitivity to IR exposure, which involves induction of apoptosis.

Conclusion

Studies in this report suggest that Rac1 GTPase plays an essential role in the activation of IR-induced ERK1/2 signaling and subsequent G₂/M checkpoint response. Furthermore, results also support a role for Rac1 in promoting cell survival after irradiation treatment.     

Daratumumab With Cetrelimab,an Anti–PD-1 Monoclonal Antibody,in Relapsed/Refractory Multiple Myeloma

BackgroundDaratumumab is approved for relapsed or refractory multiple myeloma (RRMM) as monotherapy or in combination regimens. We evaluated daratumumab plus cetrelimab, a programmed death receptor-1 inhibitor, in RRMM.Patients and MethodsThis open-label, multiphase study enrolled adults with RRMM with ≥ 3 prior lines of therapy. Part 1 was a safety run-in phase examining dose-limiting toxicities of daratumumab (16 mg/kg intravenously weekly for cycles 1-2, biweekly for cycles 3-6, and monthly thereafter) plus cetrelimab (240 mg intravenously biweekly, all cycles). In Parts 2 and 3, patients were to be randomized to daratumumab with or without cetrelimab (same schedule as Part 1). Endpoints included safety, overall response rate, pharmacokinetics, and biomarker analyses.ResultsNine patients received daratumumab plus cetrelimab in the safety run-in, and 1 received daratumumab in Part 2 before administrative study termination following a data monitoring committee’s global recommendation to stop any trial including daratumumab combined with inhibitors of programmed death receptor-1 or its ligand (programmed death-ligand 1). The median follow-up times were 6.7 months (safety run-in) and 0.3 months (Part 2). No dose-limiting toxicities occurred. All 10 patients had ≥ 1 treatment-emergent adverse event; 7 patients had grade 3 to 4 treatment-emergent adverse events, and none led to treatment discontinuation or death. In the safety run-in, 7 (77.7%) patients had ≥ 1 infusion-related reaction (most grade 1-2), and 1 had a grade 2 immune-mediated reaction. Among safety run-in patients, the overall response rate was 44.4%.ConclusionsNo new safety concerns were identified for daratumumab plus cetrelimab in RRMM. The short study duration and small population limit complete analysis of this combination.     

Analgesic-antitumor peptide inhibits the migration and invasion of HepG2 cells by an upregulated VGSC β1 subunit

Tumor Biology - Analgesic-antitumor peptide (AGAP), one of the scorpion toxin polypeptides, has been shown to have an antitumor activity. Recombinant AGAP (rAGAP) was shown to affect the migration...