POMC maintains tumor‐initiating properties of tumor tissue‐derived long‐term‐cultured breast cancer stem cells

The identification and understanding of the molecular network of cancer stem cells (CSCs) have had a profound impact on our view of carcinogenesis and treatment strategy. Unfortunately, a major problem is that serial passages of CSCs from clinical solid tumor specimens currently are not available in any lab, and thus, reported data are difficult to confirm and intensively interrogated. Here, we have generated two tumor tissue‐derived breast CSC (BCSC) lines that showed prolonged maintenance over 20 serial passages in vitro , while retaining their tumor‐initiating biological properties. We then deciphered the intrinsic mechanism using analyses of mRNA expression array profiles. It has been determined that pro‐opiomelanocortin (POMC) is closely related with protein phosphorylation mediated by G‐protein‐coupled estrogen receptor (GPER) in BCSC. Following, knockdown of POMC inhibits properties of mammosphere formation, CD44⁺CD24^? population, CD44 expression, and clonogenicity ability in BCSC. We found that inhibition of POMC attenuates phosphorylation of AKT2 and GSK3β in BCSC. Further in vivo investigations demonstrated that POMC interference regulates proliferation of BCSC‐bearing tumors. Combination of the clinical results that POMC positive expression is frequently upregulated in human breast cancer and POMC positivity correlated with a poor prognosis, POMC is a potential therapeutic target for BCSC. In conclusion, we have successfully established two long‐term‐cultured BCSC from clinical specimens. We further indicated that POMC acts as a potential therapeutic target and prognostic marker for future treatment of BCSC.     

Follicular lymphoma: State‐of‐the‐art ICML workshop in Lugano 2015

The 13th International Conference on Malignant Lymphoma held in Lugano in June 2015 was preceded by a closed workshop (organized in collaboration with the American Association for Cancer Research and the European School of Oncology) with the aim of developing an up‐to‐date understanding of the biology of follicular lymphoma and the clinical implications of new findings in the field. Discussed topics included the mutational spectrum at diagnosis, the clinical correlates of genetic and epigenetic alterations, the mechanisms of clonal evolution and histological transformation, the cross talk between tumor cells and microenvironment, and the development of novel treatments. This report represents a summary of the workshop.     

Rectal cancer staging: An up‐to‐date pictorial review

Colorectal cancer is the third most common malignancy worldwide, and rectal cancer (RC) accounts for 29% of all cases. Local staging of RC is crucial for the purposes of addressing patients appropriately to surgery alone or to preoperative chemoradiotherapy (pCRT) followed by total mesorectal excision (TME). Combined pCRT and TME may negatively affect rectal function, so rectum‐sparing approaches such as transanal local excision have been proposed as an alternative to TME for patients showing a major or complete clinical response on restaging after pCRT. Magnetic resonance imaging (MRI) has a fundamental role in the local staging and restaging of RC, with or without positron emission tomography (PET). PET/MRI enables a multiplanar high‐resolution morphological study of the pelvis, providing important information on cell density and metabolic activity with diffusion‐weighted imaging (DWI) and ¹⁸F fluorodeoxyglucose uptake respectively. This article offers a pictorial review of the MRI anatomy of the ano‐rectal region and an update on local RC staging with a hybrid ¹⁸F‐FDG PET/MRI scan.     

Radical radiotherapy with high‐dose‐rate brachytherapy for uterine cervix cancer long‐term results†

The aim of this is to report the results of radical radiotherapy in carcinoma of the cervix treated by high‐dose rate (HDR) intracavitary brachytherapy and external beam radiotherapy (XRT) at a single centre in Singapore. This is a retrospective analysis of 106 consecutive cases with histologically proven cervical cancer, treated by HDR brachytherapy and XRT at the Mount Elizabeth Hospital from 1990 to 1993. External beam radiotherapy to the pelvis was delivered with 6 MV photons, to 45–50.4 Gy in 1.8 Gy fractions. High‐dose‐rate brachytherapy comprised two to three applications of an intrauterine tandem with paired ovoids, to a median dose of 18 Gy to point ‘A’, carried out during XRT. All 106 patients completed treatment. Their ages ranged from 32 to 80 years (median 57 years). Most patients presented with stage II or III disease (44 and 37%, respectively) and with squamous cell carcinoma (91%). Median follow‐up time was 59 months (range 2–169 months). The 5‐year relapse‐free survival rate across all stages was 71%. The corresponding overall survival rate was 69%. Local control was achieved in 86 patients (81%); six patients had residual disease (6%), and 14 patients had local recurrence (13%). Fourteen patients developed metastatic disease (13%). On univariate analysis, tumour stage, haemoglobin level, number of brachytherapy treatments and overall treatment time were found to be prognostic factors for overall survival. Late complications were mild (Radiation Therapy Oncology Group score 1–2), except for one patient with grade 4 rectal toxicity. The complication rates were 8, 14 and 45%, respectively, for the rectum, bladder and vagina (stenosis). The use of two to three fractions of HDR intracavitary brachytherapy in addition to pelvic XRT achieves good outcomes.     

Cause‐specific long‐term mortality in survivors of childhood cancer in Switzerland: A population‐based study

Survivors of childhood cancer have a higher mortality than the general population. We describe cause‐specific long‐term mortality in a population‐based cohort of childhood cancer survivors. We included all children diagnosed with cancer in Switzerland (1976–2007) at age 0–14 years, who survived ≥5 years after diagnosis and followed survivors until December 31, 2012. We obtained causes of death (COD) from the Swiss mortality statistics and used data from the Swiss general population to calculate age‐, calendar year‐, and sex‐standardized mortality ratios (SMR), and absolute excess risks (AER) for different COD, by Poisson regression. We included 3,965 survivors and 49,704 person years at risk. Of these, 246 (6.2%) died, which was 11 times higher than expected (SMR 11.0). Mortality was particularly high for diseases of the respiratory (SMR 14.8) and circulatory system (SMR 12.7), and for second cancers (SMR 11.6). The pattern of cause‐specific mortality differed by primary cancer diagnosis, and changed with time since diagnosis. In the first 10 years after 5‐year survival, 78.9% of excess deaths were caused by recurrence of the original cancer (AER 46.1). Twenty‐five years after diagnosis, only 36.5% (AER 9.1) were caused by recurrence, 21.3% by second cancers (AER 5.3) and 33.3% by circulatory diseases (AER 8.3). Our study confirms an elevated mortality in survivors of childhood cancer for at least 30 years after diagnosis with an increased proportion of deaths caused by late toxicities of the treatment. The results underline the importance of clinical follow‐up continuing years after the end of treatment for childhood cancer.     

Smoking,snus use and risk of right‐ and left‐sided colon,rectal and anal cancer: A 37‐year follow‐up study

Although some authorities consider smoking to be an established risk factor for colorectal cancer, the international literature is not entirely consistent. Further, only 1 study has addressed the association with smokeless tobacco and none with Scandinavian moist snuff (snus). This retrospective cohort study included 336,381 male Swedish construction workers with detailed information on tobacco use at cohort entry in 1971–1992. Complete follow‐up through 2007 was accomplished by means of linkage to population and health registers. Hazard ratios (HRs) and 95% confidence intervals (CIs) derived from Cox proportional hazards regression models estimated relative risks, adjusted for age and body mass index. Subjects who were never‐users of any tobacco served as reference. After up to 37 years of follow‐up, pure smoking was associated with a marginally increased risk of colon cancer (HR 1.08, 95% CI 0.99–1.19), a modestly elevated risk of rectal cancer (HR 1.16, 95% CI 1.04–1.30) and a substantial excess risk of anal cancer (HR 2.41, 95% CI 1.06–5.48). Snus use was not significantly associated with an increased risk of colorectal or anal cancer, although the point estimate for colon cancer was similar to that observed among smokers. Swedish data provide meager support for the association between tobacco use and colorectal cancer. A general tendency among Swedish men to quit smoking in recent decades might have attenuated true associations. A link between smoking and anal cancer was confirmed.     

MAGE‐A10 cancer/testis antigen is highly expressed in high‐grade non‐muscle‐invasive bladder carcinomas

Bladder cancer is a common urinary malignancy and a prevalent cause of cancer‐related death. Current therapies of early stage non‐muscle‐invasive bladder cancer (NMIBC) are frequently associated with undesirable toxicities and recurrence. Active antigen‐specific immunotherapy may provide a valid therapeutic option for patients with NMIBC. Cancer‐testis antigens (CTA) expressed in various tumour types and in a limited range of healthy tissues may represent potential targets for specific immunotherapy. MAGE‐A10 is probably the most immunogenic antigen of the MAGE‐A family. We evaluated the expression of MAGE‐A10 in NMIBC. Seventy‐nine patients undergoing surgical treatment for NMIBC were enrolled in the study. MAGE‐A10 gene expression was assessed by quantitative real‐time polymerase chain reaction. Immunohistochemistry was performed on paraffin‐embedded sections. MAGE‐A10 gene was specifically expressed in one‐third of NMIBC (n = 24: 32.43%). Gene expression was correlated with high tumour grade. MAGE‐A10 protein was exclusively detectable in nuclei of tumour cells. More importantly, MAGE‐A10 protein was also more frequently detectable in high‐grade tumours (p = 0.0001) and in stage T1 tumours invading subepithelial tissue or lamina propria (p = 0.01). A strong correlation between MAGE‐A10 staining score and tumour grade and stage could accordingly be observed. These data indicate that MAGE‐A10 expression is a feature of aggressive NMIBC and might be used as a novel target for specific immunotherapy of these cancers.     

The impact of risk‐reducing hysterectomy and bilateral salpingo‐oophorectomy on survival in patients with a history of breast cancer—A population‐based data linkage study

Prophylactic surgery including hysterectomy and bilateral salpingo‐oophorectomy (BSO) is recommended in breast cancer susceptibility gene (BRCA)‐positive women, whereas in women from the general population, hysterectomy plus BSO may increase the risk of overall mortality. The effect of hysterectomy plus BSO on women previously diagnosed with breast cancer is unknown. We used data from a population‐base data linkage study of all women diagnosed with primary breast cancer in Queensland, Australia between 1997 and 2008 (n = 21,067). We fitted flexible parametric breast cancer‐specific and overall survival models with 95% confidence intervals (also known as Royston–Parmar models) to assess the impact of risk‐reducing surgery (removal of uterus, one or both ovaries). We also stratified analyses by age 20–49 and 50–79 years, respectively. Overall, 1,426 women (7%) underwent risk‐reducing surgery (13% of premenopausal women and 3% of postmenopausal women). No women who had risk‐reducing surgery compared to 171 who did not have risk‐reducing surgery developed a gynaecological cancer. Overall, 3,165 (15%) women died, including 2,195 (10%) from breast cancer. Hysterectomy plus BSO was associated with significantly reduced risk of death overall [adjusted hazard ration (HR), 0.69; 95% confidence interval (CI), 0.53–0.89; p = 0.005]. Risk reduction was greater among premenopausal women, whose risk of death halved (HR, 0.45; 95% CI, 0.25–0.79; p < 0.006). This was largely driven by reduction in breast cancer‐specific mortality (HR, 0.43; 95% CI, 0.24–0.79; p < 0.006). This population‐based study found that risk‐reducing surgery halved the mortality risk for premenopausal breast cancer patients. Replication of our results in independent cohorts and subsequently randomised trials are needed to confirm these findings.     

Targeting breast cancer‐initiating/stem cells with melanoma differentiation‐associated gene‐7/interleukin‐24

Melanoma differentiation‐associated gene‐7/interleukin‐24 (mda‐7/IL‐24) displays a broad range of antitumor properties including cancer‐specific induction of apoptosis, inhibition of tumor angiogenesis and modulation of antitumor immune responses. In our study, we elucidated the role of MDA‐7/IL‐24 in inhibiting growth of breast cancer‐initiating/stem cells. Ad.mda‐7 infection decreased proliferation of breast cancer‐initiating/stem cells without affecting normal breast stem cells. Ad.mda‐7 induced apoptosis and endoplasmic reticulum stress in breast cancer‐initiating/stem cells similar to unsorted breast cancer cells and inhibited the self‐renewal property of breast cancer‐initiating/stem cells by suppressing Wnt/β‐catenin signaling. Prevention of inhibition of Wnt signaling by LiCl increased cell survival upon Ad.mda‐7 treatment, suggesting that Wnt signaling inhibition might play a key role in MDA‐7/IL‐24‐mediated death of breast cancer‐initiating/stem cells. In a nude mouse subcutaneous xenograft model, Ad.mda‐7 injection profoundly inhibited growth of tumors generated from breast cancer‐initiating/stem cells and also exerted a potent “bystander” activity inhibiting growth of distant uninjected tumors. Further studies revealed that tumor growth inhibition by Ad.mda‐7 was associated with a decrease in proliferation and angiogenesis, two intrinsic features of MDA‐7/IL‐24, and a reduction in vivo in the percentage of breast cancer‐initiating/stem cells. Our findings demonstrate that MDA‐7/IL‐24 is not only nontoxic to normal cells and normal stem cells but also can kill both unsorted cancer cells and enriched populations of cancer‐initiating/stem cells, providing further documentation that MDA‐7/IL‐24 might be a safe and effective way to eradicate cancers and also potentially establish disease‐free survival.     

Nonsteroidal anti‐inflammatory drugs

BACKGROUND:

Nonsteroidal anti‐inflammatory drug (NSAID) use has been associated with a decreased colorectal cancer (CRC) risk. However, to the best of the authors' knowledge, the effects of NSAID on clinical outcomes after CRC diagnosis are not well defined. The authors investigated the association between prediagnosis NSAID use and mortality after CRC diagnosis among women in the California Teachers Study cohort.

METHODS:

Women aged <85 years participating in the California Teachers Study, without a prior CRC diagnosis at baseline (1995‐1996), and who were diagnosed with CRC during follow‐up through December 2005, were eligible for analysis of the association between prediagnosis NSAID use and mortality. NSAID use (including aspirin and ibuprofen) was collected through a self‐administered questionnaire. Cancer occurrence was identified through California Cancer Registry linkage. Multivariate Cox proportional hazards regression models were used to estimate hazards ratios (HR) for death and 95% confidence intervals (95% CIs).

RESULTS:

Among 621 CRC patients who were identified, 64% reported no prediagnosis regular NSAID use, 17% reported use of 1 to 6 days/week, and 20% reported daily use. A duration of NSAID use <5 years was reported by 17% of patients and a use of ≥5 years was reported by 18%. Regular prediagnosis NSAID use (1‐3 days/week, 4‐6 days/week, and daily) versus none was associated with improved overall survival (OS) (HR, 0.71; 95% CI, 0.53‐0.95) and CRC‐specific survival (HR, 0.58; 95% CI 0.40‐0.84) after adjustment for clinically relevant factors. Prediagnosis NSAID use ≥5 years (vs none) was found to be associated with improved OS (HR, 0.55; 95% CI, 0.37‐0.84) and CRC‐specific survival (HR, 0.40; 95% CI, 0.23‐0.71) in adjusted analyses.

CONCLUSIONS:

When used regularly or over a prolonged duration before CRC diagnosis, NSAIDs are associated with decreased mortality among female CRC patients. Cancer 2009. © 2009 American Cancer Society.     

Restriction endonuclease‐mediated real‐time digestion‐PCR for somatic mutation detection

PCR is a powerful platform for clinical and diagnostic applications, but challenges remain in detecting somatic mutations, as mutant cells are often mixed with more numerous wild‐type cells at the tissue‐sample sites. Here, we describe a novel method that couples PCR with restriction endonuclease digestion (designated real‐time digestion‐PCR, or RTD‐PCR) in a one‐step reaction tube for detecting somatic mutations from a minority of cells. The PCR mixture contains a thermostable restriction enzyme that digests wild‐type alleles during the PCR program, allowing selective amplification of the mutant alleles. To validate this method, we used real‐time digestion‐PCR for the specific detection of the EGFR (epidermal growth factor receptor) treatment resistance‐inducing mutation, T790M, combining with three different platforms: Sanger sequencing, TaqMan probe PCR and Sequenom MassArray. From 78 clinical samples, seven T790M mutations were consistently detected on all three platforms, indicating that RTD‐PCR may be a useful clinical tool for analyzing the T790M point mutation.     

c‐Src promotes tumor progression through downregulation of microRNA‐129‐1‐3p

MicroRNAs (miRNAs) fine‐tune cellular signaling by regulating expression of signaling proteins, and aberrant expression of miRNAs is observed in many cancers. The tyrosine kinase c‐Src is upregulated in various human cancers, but the molecular mechanisms underlying c‐Src‐mediated tumor progression remain unclear. In previous investigations of miRNA‐mediated control of c‐Src‐related oncogenic pathways, we identified miRNAs that were downregulated in association with c‐Src transformation and uncovered the signaling networks by predicting their target genes, which might act cooperatively to control tumor progression. Here, to further elucidate the process of cell transformation driven by c‐Src, we analyzed the expression profiles of miRNAs in a doxycycline‐inducible Src expression system. We found that miRNA (miR)‐129‐1‐3p was downregulated in the early phase of c‐Src‐induced cell transformation, and that reexpression of miR‐129‐1‐3p disrupted c‐Src‐induced cell transformation. In addition, miR‐129‐1‐3p downregulation was tightly associated with tumor progression in human colon cancer cells/tissues. Expression of miR‐129‐1‐3p in human colon cancer cells caused morphological changes and suppressed tumor growth, cell adhesion, and invasion. We also identified c‐Src and its critical substrate Fer, and c‐Yes, a member of the Src family of kinases, as novel targets of miR‐129‐1‐3p. Furthermore, we found that miR‐129‐1‐3p‐mediated regulation of c‐Src/Fer and c‐Yes is important for controlling cell adhesion and invasion. Downregulation of miR‐129‐1‐3p by early activation of c‐Src increases expression of these target genes and synergistically promotes c‐Src‐related oncogenic signaling. Thus, c‐Src‐miR‐129‐1‐3p circuits serve as critical triggers for tumor progression in many human cancers that harbor upregulation of c‐Src.     

HB‐EGF orchestrates the complex signals involved in triple‐negative and trastuzumab‐resistant breast cancer

A number of therapeutic strategies targeting epidermal growth factor receptor (EGFR) have not always led to success in the present state of breast cancer therapy. Notably, there is currently no way to treat trastuzumab‐resistant and triple‐negative breast cancer (TNBC). Here, we found that heparin‐binding epidermal growth factor‐like growth factor (HB‐EGF), a member of the EGFR ligands, was predominantly expressed in breast cancer and that treatment with crossreacting material 197 (CRM197), a specific inhibitor of HB‐EGF, blocked ERK as well as AKT activation via complexes of EGFR and unknown growth factor receptors in TNBC or through complexes of EGFR and human epidermal growth factor receptor‐2 in trastuzumab‐resistant breast cancer, caused significant cell apoptosis and inhibited tumor growth. Accordingly, we can provide a novel concept that a certain EGFR ligand is recognized as a rational target against breast cancer. In addition, it is plausible that CRM197 could be an effective anticancer agent for molecularly targeted therapies.     

Population‐based 10‐year oncologic outcomes after low‐dose‐rate brachytherapy for low‐risk and intermediate‐risk prostate cancer

BACKGROUND.

The objective of this study was to report the rates of disease‐free survival (DFS), cause‐specific survival (CSS), and overall survival after low‐dose‐rate (LDR) prostate brachytherapy (PB).

METHODS.

Data from 1006 consecutive patients with prostate cancer who received LDR‐PB and underwent implantation on or before October 23, 2003 were extracted from a prospective database on November 11, 2011. The selected patients had low‐risk (58%) or intermediate‐risk (42%) disease according to National Comprehensive Cancer Network criteria. The Phoenix threshold was used to define biochemical relapse. Sixty‐five percent of patients received 3 months of neoadjuvant androgen‐deprivation therapy (ADT) and 3 months of concomitant ADT. Univariate and multivariate analyses are reported in relation to patient, tumor, and treatment variables.

RESULTS.

The median follow‐up was 7.5 years. By using Fine and Gray competing risks analysis, the 5‐year and 10‐year actuarial DFS rates were 96.7% (95% confidence interval, 95.2%‐97.7%) and 94.1% (95% confidence interval, 92%‐95.6%), respectively. When applied to the whole cohort, none of the usual prognostic variables, including dose metrics, were correlated with DFS. However, in both univariate and multivariate models, increasing dose was the only covariate that correlated with improved DFS for the subset of men (N = 348) who did not receive ADT (P = .043). The actuarial 10‐year CSS rate was 99.1% (95% confidence interval, 97.3%‐99.7%). The overall survival rate was 93.8% at 5 years (95% confidence interval, 92%‐95.1%) and 83.5% at 10 years (95% confidence interval, 79.8%‐86.6%). Only age at implantation (P = .0001) was correlated with overall survival in multivariate analysis.

CONCLUSIONS.

In a consecutive cohort of 1006 men with National Comprehensive Cancer Network low‐risk and intermediate‐risk prostate cancer, the actuarial rate of recurrent disease after LDR‐PB was approximately 3% at 5 years and 6% at 10 years. Cancer 2013. © 2012 American Cancer Society.     

Oncogenic microRNA‐27a is a target for anticancer agent methyl 2‐cyano‐3,11‐dioxo‐18β‐olean‐1,12‐dien‐30‐oate in colon cancer cells

Methyl 2‐cyano‐3,11‐dioxo‐18β‐olean‐1,12‐dien‐30‐oate (CDODA‐Me) is a synthetic derivative of glycyrrhetinic acid, a triterpenoid phytochemical found in licorice extracts. CDODA‐Me inhibited growth of RKO and SW480 colon cancer cells and this was accompanied by decreased expression of Sp1, Sp3 and Sp4 protein and mRNA and several Sp‐dependent genes including survivin, vascular endothelial growth factor (VEGF), and VEGF receptor 1 (VEGFR1 or Flt‐1). CDODA‐Me also induced apoptosis, arrested RKO and SW480 cells at G₂/M, and inhibited tumor growth in athymic nude mice bearing RKO cells as xenografts. CDODA‐Me decreased expression of microRNA‐27a (miR‐27a), and this was accompanied by increased expression of 2 miR‐27a‐regulated mRNAs, namely ZBTB10 (an Sp repressor) and Myt‐1 which catalyzes phosphorylation of cdc2 to inhibit progression of cells through G₂/M. Both CDODA‐Me and antisense miR‐27a induced comparable responses in RKO and SW480 cells, suggesting that the potent anticarcinogenic activity of CDODA‐Me is due to repression of oncogenic miR‐27a. © 2009 UICC     

Periodontitis and cancer mortality: Register‐based cohort study of 68,273 adults in 10‐year follow‐up

Periodontitis, a multifactorial infection‐induced low‐grade chronic inflammation, can influence the process of carcinogenesis. We studied with 10 years follow‐up of 68,273 adults‐based cohort the involvement of periodontitis as a risk factor for cancer mortality. Periodontal status was defined based on procedure codes of periodontal treatment. Rate ratios and absolute differences of overall and cancer mortality rates were assessed with respect to periodontal status using multiplicative and additive Poisson regression models, respectively. We adjusted for effect of age, sex, calendar time, socio‐economic status, oral health, dental treatments and diabetes. Data about smoking or alcohol consumption were not available. Altogether 797 cancer deaths occurred during 664,020 person‐years accumulated over a mean 10.1‐year follow‐up. Crude cancer mortality rate per 10,000 person‐years for participants without and with periodontitis was 11.36 (95% CI 10.47–12.31) and 14.45 (95% CI 12.51–16.61), respectively. Crude rate ratios for periodontitis indicated an increased risk of overall (RR 1.27, 95% CI 1.08–1.39) and pancreatic cancer (RR 1.69, 95% CI 1.04–2.76) mortality. After adjustment, the results showed even stronger associations of periodontitis with increased overall (RR 1.33, 95% CI 1.10–1.58) and pancreatic cancer (RR 2.32, 95% CI 1.31–3.98) mortality. A higher pancreatic cancer mortality among individuals with periodontitis contributed considerably to the difference in overall cancer mortality, but this difference was not due to pancreatic cancer deaths alone.