Inhibition of the JAK2/STAT3 pathway in ovarian cancer results in the loss of cancer stem cell-like characteristics and a reduced tumor burden

Background Current treatment of ovarian cancer patients with chemotherapy leaves behind a residual tumor which results in recurrent ovarian cancer within a short time frame. We have previously demonstrated that a single short-term treatment of ovarian cancer cells with chemotherapy in vitro resulted in a cancer stem cell (CSC)-like enriched residual population which generated significantly greater tumor burden compared to the tumor burden generated by control untreated cells. In this report we looked at the mechanisms of the enrichment of CSC-like residual cells in response to paclitaxel treatment. Methods The mechanism of survival of paclitaxel-treated residual cells at a growth inhibitory concentration of 50% (GI50) was determined on isolated tumor cells from the ascites of recurrent ovarian cancer patients and HEY ovarian cancer cell line by in vitro assays and in a mouse xenograft model. Results Treatment of isolated tumor cells from the ascites of ovarian cancer patients and HEY ovarian cancer cell line with paclitaxel resulted in a CSC-like residual population which coincided with the activation of Janus activated kinase 2 (JAK2) and signal transducer and activation of transcription 3 (STAT3) pathway in paclitaxel surviving cells. Both paclitaxel-induced JAK2/STAT3 activation and CSC-like characteristics were inhibited by a low dose JAK2-specific small molecule inhibitor CYT387 (1 μM) in vitro. Subsequent, in vivo transplantation of paclitaxel and CYT387-treated HEY cells in mice resulted in a significantly reduced tumor burden compared to that seen with paclitaxel only-treated transplanted cells. In vitro analysis of tumor xenografts at protein and mRNA levels demonstrated a loss of CSC-like markers and CA125 expression in paclitaxel and CYT387-treated cell-derived xenografts, compared to paclitaxel only-treated cell-derived xenografts. These results were consistent with significantly reduced activation of JAK2 and STAT3 in paclitaxel and CYT387-treated cell-derived xenografts compared to paclitaxel only-treated cell derived xenografts. Conclusions This proof of principle study demonstrates that inhibition of the JAK2/STAT3 pathway by the addition of CYT387 suppresses the ‘stemness’ profile in chemotherapy-treated residual cells in vitro, which is replicated in vivo, leading to a reduced tumor burden. These findings have important implications for ovarian cancer patients who are treated with taxane and/or platinum-based therapies. Keywords: Ovarian carcinoma, Cancer stem cell, Metastasis, Ascites, Chemoresistance, Recurrence, JAK2/STAT3 pathway

Targeted disruption of the JAK2/STAT3 pathway in combination with systemic administration of paclitaxel inhibits the priming of ovarian cancer stem cells leading to a reduced tumor burden

Chemotherapy resistance associated with recurrent disease is the major cause of poor survival of ovarian cancer patients. We have recently demonstrated activation of the JAK2/STAT3 pathway and the enhancement of a cancer stem cell (CSC)-like phenotype in ovarian cancer cells treated in vitro with chemotherapeutic agents. To elucidate further these mechanisms in vivo,we used a two-tiered paclitaxel treatment approach in nude mice inoculated with ovarian cancer cells. In the first approach, we demonstrate that a single intraperitoneal administration of paclitaxel in mice 7 days after subcutaneous transplantation of the HEY ovarian cancer cell line resulted in a significant increase in the expression of CA125, Oct4, and CD117 in mice xenografts compared to control mice xenografts which did not receive paclitaxel. In the second approach, mice were administered once weekly with paclitaxel and/or a daily dose of the JAK2-specific inhibitor, CYT387, over 4weeks. Mice receiving paclitaxel only demonstrated a significant decrease in tumor volume compared to control mice. At the molecular level, mouse tumors remaining after paclitaxel administration showed a significant increase in the expression of Oct4 and CD117 coinciding with a significant activation of the JAK2/STAT3 pathway compared to control tumors. The addition of CYT387 with paclitaxel resulted in the suppression of JAK2/STAT3 activation and abrogation of Oct4 and CD117 expression in mouse xenografts. This coincided with significantly smaller tumors in mice administered CYT387 in addition to paclitaxel, compared to the control group and the group of mice receiving paclitaxel only. These data suggest that the systemic administration of paclitaxel enhances Oct4- and CD117-associated CSC-like marker expression in surviving cancer cells in vivo, which can be suppressed by the addition of the JAK2-specific inhibitor CYT387, leading to a significantly smaller tumor burden. These novel findings have the potential for the development of CSC-targeted therapy to improve the treatment outcomes of ovarian cancer patients.

Influence of polymorphisms of GSTM1 and GSTT1 for risk of renal cell cancer in workers with long-term high occupational exposure to trichloroethene

Suspected nephrocarcinogenic effects of trichloroethene (TRI) in humans are attributed to metabolites derived from the glutathione transferase (GST) pathway. The influence of polymorphisms of GSTM1 and GSTT1 isoenzymes on the risk of renal cell cancer in subjects having been exposed to high levels of TRI over many years was investigated. GSTM1 and GSTT1 genotypes were determined by internal standard controlled polymerase chain reaction. Fourty-five cases with histologically verified renal cell cancer and a history of long-term occupational exposure to high concentrations of TRI were studied. A reference group consisted of 48 workers from the same geographical region with similar histories of occupational exposures to TRI but not suffering from any cancer. Among the 45 renal cell cancer patients, 27 carried at least one functional GSTM1 (GSTM1 +) and 18 at least one functional GSTT1 (GSTT1 +). Among the 48 reference workers, 17 were GSTM1 + and 31 were GSTT1 +. Odds ratios for renal cell cancer were 2.7 for GSTM1 + individuals (95% CI, 1.18-6.33; P < 0.02) and 4.2 for GSTT1 + individuals (95% CI, 1.16-14.91; P < 0.05), respectively. The data support the present concept of the nephrocarcinogenicity of TRI.

Glutathione transferase isozyme genotypes in patients with prostate and bladder carcinoma

Genotype distributions for GSTP1, GSTM1, and GSTT1 were determined in 91 patients with prostatic carcinoma and 135 patients with bladder carcinoma and compared with those in 127 abdominal surgery patients without malignancies. None of the genotypes differed significantly with respect to age or sex among controls or cancer patients. In the group of prostatic carcinoma patients, GSTT1 null allele homozygotes were more prevalent (25% in carcinoma patients vs 13% in controls, Fisher P=0.02, χ2 P = 0.02, OR = 2.31, CI = 1.17-4.59) and the combined M1-/T1-null genotype was also more frequent (9% vs 3%, χ2 P= 0.02, Fisher P = 0.03). Homozygosity for the GSTM1 null allele was more frequent among bladder carcinoma patients (59% in bladder carcinoma patients vs 45% in controls, Fisher P = 0.03, χ2 P = 0.02, OR = 1.76, CI = 1.08-2.88). In contrast to a previous report, no significant increase in the frequency of the GSTP1b allele was found in the tumor patients. Except for the combined GSTM1-/T1-null genotype in prostatic carcinoma, none of the combined genotypes showed a significant association with either of the cancers. These findings suggest that specific single polymorphic GST genes, that is GSTM1 in the case of bladder cancer and GSTT1 in the case of prostatic carcinoma, are most relevant for the development of these urological malignancies among the general population in Central Europe.

The glycosphingolipid P1 is an ovarian cancer-associated carbohydrate antigen involved in migration

Background The level of plasma-derived naturally circulating anti-glycan antibodies (AGA) to P1 trisaccharide has previously been shown to significantly discriminate between ovarian cancer patients and healthy women. Here we aim to identify the Ig class that causes this discrimination, to identify on cancer cells the corresponding P1 antigen recognised by circulating anti-P1 antibodies and to shed light into the possible function of this glycosphingolipid. Method An independent Australian cohort was assessed for the presence of anti-P1 IgG and IgM class antibodies using suspension array. Monoclonal and human derived anti-glycan antibodies were verified using three independent glycan-based immunoassays and flow cytometry-based inhibition assay. The P1 antigen was detected by LC-MS/MS and flow cytometry. FACS-sorted cell lines were studied on the cellular migration by colorimetric assay and real-time measurement using xCELLigence system. Results Here we show in a second independent cohort (n=155) that the discrimination of cancer patients is mediated by the IgM class of anti-P1 antibodies (P=0.0002). The presence of corresponding antigen P1 and structurally related epitopes in fresh tissue specimens and cultured cancer cells is demonstrated. We further link the antibody and antigen (P1) by showing that human naturally circulating and affinity-purified anti-P1 IgM isolated from patients ascites can bind to naturally expressed P1 on the cell surface of ovarian cancer cells. Cell-sorted IGROV1 was used to obtain two study subpopulations (P1-high, 66.1%; and P1-low, 33.3%) and observed that cells expressing high P1-levels migrate significantly faster than those with low P1-levels. Conclusions This is the first report showing that P1 antigen, known to be expressed on erythrocytes only, is also present on ovarian cancer cells. This suggests that P1 is a novel tumour-associated carbohydrate antigen recognised by the immune system in patients and may have a role in cell migration. The clinical value of our data may be both diagnostic and prognostic; patients with low anti-P1 IgM antibodies present with a more aggressive phenotype and earlier relapse.

The establishment of an ISO compliant cancer biobank for Jordan and its neighboring countries through knowledge transfer and training

Research studies aimed at advancing cancer prevention, diagnosis, and treatment depend on a number of key resources, including a ready supply of high-quality annotated biospecimens from diverse ethnic populations that can be used to test new drugs, assess the validity of prognostic biomarkers, and develop tailor-made therapies. In November 2011, KHCCBIO was established at the King Hussein Cancer Center (KHCC) with the support of Seventh Framework Programme (FP7) funding from the European Union (khccbio.khcc.jo). KHCCBIO was developed for the purpose of achieving an ISO accredited cancer biobank through the collection, processing, and preservation of high-quality, clinically annotated biospecimens from consenting cancer patients, making it the first cancer biobank of its kind in Jordan. The establishment of a state-of-the-art, standardized biospecimen repository of matched normal and lung tumor tissue, in addition to blood components such as serum, plasma, and white blood cells, was achieved through the support and experience of its European partners, Trinity College Dublin, Biostor Ireland, and accelopment AG. To date, KHCCBIO along with its partners, have worked closely in establishing an ISO Quality Management System (QMS) under which the biobank will operate. A Quality Policy Manual, Validation, and Training plan have been developed in addition to the development of standard operating procedures (SOPs) for consenting policies on ethical issues, data privacy, confidentiality, and biobanking bylaws. SOPs have also been drafted according to best international practices and implemented for the donation, procurement, processing, testing, preservation, storage, and distribution of tissues and blood samples from lung cancer patients, which will form the basis for the procurement of other cancer types. KHCCBIO will be the first ISO accredited cancer biobank from a diverse ethnic Middle Eastern and North African population. It will provide a unique and valuable resource of high-quality human biospecimens and anonymized clinicopathological data to the cancer research communities world-wide.

Systematic review of pharmacologic and non-pharmacologic interventions to manage cognitive alterations after chemotherapy for breast cancer

Purpose Cognitive alterations are reported in breast cancer patients receiving chemotherapy. This has adverse effects on patients’ quality of life and function. This systematic review investigates the effectiveness of pharmacologic and non-pharmacologic interventions to manage cognitive alterations associated with breast cancer treatment. Methods Medline via EBSCOhost, CINAHL and Cochrane CENTRAL were searched for the period January 1999 to May 2014 for prospective randomized controlled trials related to the management of chemotherapy-associated cognitive alterations. Included studies investigated the management of chemotherapy-associated cognitive alterations and used subjective or objective measures in patients with breast cancer during or after chemotherapy. Two authors independently extracted data and assessed the risk of bias. Results Thirteen studies involving 1138 participants were included. Overall, the risk of bias for the 13 studies were either high (n=11) or unclear (n=2). Pharmacologic interventions included psychostimulants (n=4), epoetin alfa (n=1), and Ginkgo biloba (n=1). Non-pharmacologic interventions were cognitive training (n=5) and physical activity (n=2). Pharmacologic agents were ineffective except for self-reported cognitive function in an epoetin alfa study. Cognitive training interventions demonstrated benefits in self-reported cognitive function, memory, verbal function and language and orientation/attention. Physical activity interventions were effective in improving executive function and self-reported concentration. Conclusion Current evidence does not favor the pharmacologic management of cognitive alterations associated with breast cancer treatment. Cognitive training and physical activity interventions appear promising, but additional studies are required to establish their efficacy. Further research is needed to overcome methodological shortfalls such as heterogeneity in participant characteristics and non-standardized neuropsychological outcome measures.

Photon beam dose distributions for patients with implanted temporary tissue expanders

This study examines the effects of temporary tissue expanders (TTEs) on the dose distributions of photon beams in breast cancer radiotherapy treatments. EBT2 radiochromic film and ion chamber measurements were taken to quantify the attenuation and backscatter effects of the inhomogeneity. Results illustrate that the internal magnetic port present in a tissue expander causes a dose reduction of approximately 25% in photon tangent fields immediately downstream of the implant. It was also shown that the silicone elastomer shell of the tissue expander reduced the dose to the target volume by as much as 8%. This work demonstrates the importance for an accurately modelled high-density implant in the treatment planning system for post-mastectomy breast cancer patients.

Parent feeding interactions and practices during childhood cancer treatment: A qualitative investigation

In the general population it is evident that parent feeding practices can directly shape a child’s life long dietary intake. Young children undergoing childhood cancer treatment may experience feeding difficulties and limited food intake, due to the inherent side effects of their anti-cancer treatment. What is not clear is how these treatment side effects are influencing the parent–child feeding relationship during anti-cancer treatment. This retrospective qualitative study collected telephone based interview data from 38 parents of childhood cancer patients who had recently completed cancer treatment (child’s mean age: 6.98 years). Parents described a range of treatment side effects that impacted on their child’s ability to eat, often resulting in weight loss. Sixty-one percent of parents (n = 23) reported high levels of stress in regard to their child’s eating and weight loss during treatment. Parents reported stress, feelings of helplessness, and conflict and/or tension between parent and the child during feeding/eating interactions. Parents described using both positive and negative feeding practices, such as: pressuring their child to eat, threatening the insertion of a nasogastric feeding tube, encouraging the child to eat and providing home cooked meals in hospital. Results indicated that parent stress may lead to the use of coping strategies such as positive or negative feeding practices to entice their child to eat during cancer treatment. Future research is recommended to determine the implication of parent feeding practice on the long term diet quality and food preferences of childhood cancer survivors.

Latent class analysis reveals distinct subgroups of patients based on symptom occurrence and demographic and clinical characteristics

Context Cancer patients experience a broad range of physical and psychological symptoms as a result of their disease and its treatment. On average, these patients report ten unrelieved and co-occurring symptoms. Objectives To determine if subgroups of oncology outpatients receiving active treatment (n=582) could be identified based on their distinct experience with thirteen commonly occurring symptoms; to determine whether these subgroups differed on select demographic, and clinical characteristics; and to determine if these subgroups differed on quality of life (QOL) outcomes. Methods Demographic, clinical, and symptom data from one Australian and two U.S. studies were combined. Latent class analysis (LCA) was used to identify patient subgroups with distinct symptom experiences based on self-report data on symptom occurrence using the Memorial Symptom Assessment Scale (MSAS). Results Four distinct latent classes were identified (i.e., All Low (28.0%), Moderate Physical and Lower Psych (26.3%), Moderate Physical and Higher Psych (25.4%), All High (20.3%)). Age, gender, education, cancer diagnosis, and presence of metastatic disease differentiated among the latent classes. Patients in the All High class had the worst QOL scores. Conclusion Findings from this study confirm the large amount of interindividual variability in the symptom experience of oncology patients. The identification of demographic and clinical characteristics that place patients are risk for a higher symptom burden can be used to guide more aggressive and individualized symptom management interventions.

Associations between ghrelin and ghrelin receptor polymorphisms and cancer in Caucasian populations: A meta-analysis

Background There is growing evidence that the ghrelin axis, including ghrelin (GHRL) and its receptor, the growth hormone secretagogue receptor (GHSR), play a role in cancer progression. Ghrelin gene and ghrelin receptor gene polymorphisms have been reported to have a range of effects in cancer, from increased risk, to protection from cancer, or having no association. In this study we aimed to clarify the role of ghrelin and ghrelin receptor polymorphisms in cancer by performing a meta-analysis of published case–control studies. We conducted searches of the literature published up to January 2013 in MEDLINE using the PubMed search engine. Individual data on 8,430 cases and 14,008 controls from six case–control studies of an all Caucasian population were evaluated for three ghrelin gene (GHRL; rs696217, rs4684677, rs2075356) and one ghrelin receptor (GHSR; rs572169) polymorphism in breast cancer, esophageal cancer, colorectal cancer and non-Hodgkins lymphoma. Results In the overall analysis, homozygous and recessive associations indicated that the minor alleles of rs696217 and rs2075356 GHRL polymorphisms conferred reduced cancer risk (odds ratio [OR] 0.61-0.78). The risk was unchanged for breast cancer patients when analysed separately (OR 0.73-0.83). In contrast, the rs4684677 GHRL and the rs572169 GHSR polymorphisms conferred increased breast cancer risk (OR 1.97-1.98, p = 0.08 and OR 1.42-1.43, p = 0.08, respectively). All dominant and co-dominant effects showed null effects (OR 0.96-1.05), except for the rs572169 co-dominant effect, with borderline increased risk (OR 1.08, p = 0.05). Conclusions This study suggests that the rs696217 and rs2075356 ghrelin gene (GHRL) polymorphisms may protect carriers against breast cancer, and the rs4684677 GHRL and rs572169 GHSR polymorphisms may increase the risk among carriers. In addition, larger studies are required to confirm these findings.

Improving muscular endurance with the MVe Fitness ChairTM in breast cancer survivors: A feasibility and efficacy study

Objectives To assess the feasibility and efficacy of delivering Pilates exercises for resistance training to breast cancer survivors using the MVe Fitness Chair™. Design Pilot randomized controlled trial. Methods Twenty-six female breast cancer survivors were randomized to use the MVe Fitness Chair™ (n = 8), traditional resistance training (n = 8), or a control group (no exercise) (CO) (n = 10). The MVe Fitness Chair™ and traditional resistance training groups completed 8 weeks of exercise. Muscular endurance was assessed pre and post-test for comparisons within and between groups using push ups, curl ups, and the Dynamic Muscular Endurance Test Battery for Cancer Patients of Various Ages. Results Feasibility of the MVe Fitness Chair™ was good, evidenced by over 80% adherence for both exercise groups and positive narrative feedback. Significant improvements in muscular endurance were observed in the MVe Fitness Chair™ (p < 0.002) and traditional resistance training groups (p < 0.001), but there were no differences in improvement between the MVe Fitness Chair™ and traditional resistance training groups (p < 0.711) indicating that Pilates and traditional resistance training may be equally effective at improving muscular endurance in this population. Conclusions The MVe Fitness Chair™ is feasible for use in breast cancer survivors. It appears to promote similar improvements in muscular endurance when compared to traditional resistance training, but has several advantages over traditional resistance training, including cost, logistics, enjoyment, and ease of learning.

Refining prognosis and identifying targetable pathways for high-risk endometrial cancer; a TransPORTEC initiative

This study aimed to investigate whether molecular analysis can be used to refine risk assessment, direct adjuvant therapy, and identify actionable alterations in high-risk endometrial cancer. TransPORTEC, an international consortium related to the PORTEC3 trial, was established for translational research in high-risk endometrial cancer. In this explorative study, routine molecular analyses were used to detect prognostic subgroups: p53 immunohistochemistry, microsatellite instability and POLE proofreading mutation. Furthermore, DNA was analyzed for hotspot mutations in 13 additional genes (BRAF, CDKNA2, CTNNB1, FBXW7, FGFR2, FGFR3, FOXL2, HRAS, KRAS, NRAS, PIK3CA, PPP2R1A, and PTEN) and protein expression of ER, PR, PTEN, and ARID1a was analyzed. Rates of distant metastasis, recurrence-free, and overall survival were calculated using the Kaplan-Meier method and log-rank test. In total, samples of 116 high-risk endometrial cancer patients were included: 86 endometrioid; 12 serous; and 18 clear cell. For endometrioid, serous, and clear cell cancers, 5-year recurrence-free survival rates were 68%, 27%, and 50% (P=0.014) and distant metastasis rates 23%, 64%, and 50% (P=0.001), respectively. Four prognostic subgroups were identified: (1) a group of p53-mutant tumors; (2) microsatellite instable tumors; (3) POLE proofreading-mutant tumors; and (4) a group with no specific molecular profile (NSMP). In group 3 (POLE-mutant; n=14) and group 2 (microsatellite instable; n=19) patients, no distant metastasis occurred, compared with 50% distant metastasis rate in group 1 (p53-mutant; n=36) and 39% in group 4 (NSMP; P<0.001). Five-year recurrence-free survival was 93% and 95% for group 3 (POLE-mutant) and group 2 (microsatellite instable) vs 42% (group 1, p53-mutant) and 52% (group 4, NSMP; P<0.001). Targetable FBXW7 and FGFR2 mutations (6%), alterations in the PI3K-AKT pathway (60%) and hormone receptor positivity (45%) were frequently found. In conclusion, molecular analysis of high-risk endometrial cancer identifies four distinct prognostic subgroups, with potential therapeutic implications. High frequencies of targetable alterations were identified and may serve as targets for individualized treatment

The role of DNA repair pathways in cisplatin resistant lung cancer

Platinum chemotherapeutic agents such as cisplatin are currently used in the treatment of various malignancies such as lung cancer. However, their efficacy is significantly hindered by the development of resistance during treatment. While a number of factors have been reported that contribute to the onset of this resistance phenotype, alterations in the DNA repair capacity of damaged cells is now recognised as an important factor in mediating this phenomenon. The mode of action of cisplatin has been linked to its ability to crosslink purine bases on the DNA, thereby interfering with DNA repair mechanisms and inducing DNA damage. Following DNA damage, cells respond by activating a DNA-damage response that either leads to repair of the lesion by the cell thereby promoting resistance to the drug, or cell death via activation of the apoptotic response. Therefore, DNA repair is a vital target to improving cancer therapy and reduce the resistance of tumour cells to DNA damaging agents currently used in the treatment of cancer patients. To date, despite the numerous findings that differential expression of components of the various DNA repair pathways correlate with response to cisplatin, translation of such findings in the clinical setting are still warranted. The identification of alterations in specific proteins and pathways that contribute to these unique DNA repair pathways in cisplatin resistant cancer cells may potentially lead to a renewed interest in the development of rational novel therapies for cisplatin resistant cancers, in particular, lung cancer.

Predicting the need for adaptive radiotherapy in head and neck cancer

Background and purpose Adaptive radiotherapy (ART) can account for the dosimetric impact of anatomical change in head and neck cancer patients; however it can be resource intensive. Consequently, it is imperative that patients likely to require ART are identified. The purpose of this study was to find predictive factors that identify oropharyngeal squamous cell carcinoma (OPC) and nasopharyngeal carcinoma (NPC) patients more likely to need ART. Materials and methods One hundred and ten patients with OPC or NPC were analysed. Patient demographics and tumour characteristics were compared between patients who were replanned and those that were not. Factors found to be significant were included in logistic regression models. Risk profiles were developed from these models. A dosimetric analysis was performed. Results Nodal disease stage, pre-treatment largest involved node size, diagnosis and initial weight (categorised in 2 groups) were identified as significant for inclusion in the model. Two models were found to be significant (p = 0.001), correctly classifying 98.2% and 96.1% of patients respectively. Three ART risk profiles were developed. Conclusion Predictive factors identifying OPC or NPC patients more likely to require ART were reported. A risk profile approach could facilitate the effective implementation of ART into radiotherapy departments through forward planning and appropriate resource allocation.