MiR-193b promotes autophagy and non-apoptotic cell death in oesophageal cancer cells

BACKGROUND

Successful treatment of oesophageal cancer is hampered by recurrent drug resistant disease. We have previously demonstrated the importance of apoptosis and autophagy for the recovery of oesophageal cancer cells following drug treatment. When apoptosis (with autophagy) is induced, these cells are chemosensitive and will not recover following chemotherapy treatment. In contrast, when cancer cells exhibit only autophagy and limited Type II cell death, they are chemoresistant and recover following drug withdrawal.

METHODS

MicroRNA (miRNA) expression profiling of an oesophageal cancer cell line panel was used to identify miRNAs that were important in the regulation of apoptosis and autophagy. The effects of miRNA overexpression on cell death mechanisms and recovery were assessed in the chemoresistant (autophagy inducing) KYSE450 oesophageal cancer cells.

RESULTS

MiR-193b was the most differentially expressed miRNA between the chemosensitive and chemoresistant cell lines with higher expression in chemosensitive apoptosis inducing cell lines. Colony formation assays showed that overexpression of miR-193b significantly impedes the ability of KYSE450 cells to recover following 5-fluorouracil (5-FU) treatment. The critical mRNA targets of miR-193b are unknown but target prediction and siRNA data analysis suggest that it may mediate some of its effects through stathmin 1 regulation. Apoptosis was not involved in the enhanced cytotoxicity. Overexpression of miR-193b in these cells induced autophagic flux and non-apoptotic cell death.

CONCLUSION

These results highlight the importance of miR-193b in determining oesophageal cancer cell viability and demonstrate an enhancement of chemotoxicity that is independent of apoptosis induction.

Intratumoural production of TNFα by bacteria mediates cancer therapy

Systemic administration of the highly potent anticancer therapeutic, tumour necrosis factor alpha (TNFα) induces high levels of toxicity and is responsible for serious side effects. Consequently, tumour targeting is required in order to confine this toxicity within the locality of the tumour. Bacteria have a natural capacity to grow within tumours and deliver therapeutic molecules in a controlled fashion. The non-pathogenic E. coli strain MG1655 was investigated as a tumour targeting system in order to produce TNFα specifically within murine tumours. In vivo bioluminescence imaging studies and ex vivo immunofluorescence analysis demonstrated rapid targeting dynamics and prolonged survival, replication and spread of this bacterial platform within tumours. An engineered TNFα producing construct deployed in mouse models via either intra-tumoural (i.t.) or intravenous (i.v.) administration facilitated robust TNFα production, as evidenced by ELISA of tumour extracts. Tumour growth was impeded in three subcutaneous murine tumour models (CT26 colon, RENCA renal, and TRAMP prostate) as evidenced by tumour volume and survival analyses. A pattern of pro-inflammatory cytokine induction was observed in tumours of treated mice vs. controls. Mice remained healthy throughout experiments. This study indicates the therapeutic efficacy and safety of TNFα expressing bacteria in vivo, highlighting the potential of non-pathogenic bacteria as a platform for restricting the activity of highly potent cancer agents to tumours.

Clinical evaluation of macrophages in cancer: role in treatment, modulation and challenges

The focus of immunotherapeutics has been placed firmly on anti-tumour T cell responses. Significant progress has been made in the treatment of both local and systemic malignancies, but low response rates and rising toxicities are limiting this approach. Advancements in the understanding of tumour immunology are opening up a new range of therapeutic targets, including immunosuppressive factors in the tumour microenvironment. Macrophages are a heterogeneous group of cells that have roles in innate and adaptive immunity and tissue repair, but become co-opted by tumours to support tumour growth, survival, metastasis and immunosuppression. Macrophages also support tumour resistance to conventional therapy. In preclinical models, interference with macrophage migration, macrophage depletion and macrophage re-education have all been shown to reduce tumour growth and support anti-tumour immune responses. Here we discuss the role of macrophages in prognosis and sensitivity to therapy, while examining the significant progress which has been made in modulating the behaviour of these cells in cancer patients.

High Cysteinyl Leukotriene Receptor 1 Expression Correlates with Poor Survival of Uveal Melanoma Patients and Cognate Antagonist Drugs Modulate the Growth, Cancer Secretome, and Metabolism of Uveal Melanoma Cells

Metastatic uveal melanoma (UM) is a rare, but often lethal, form of ocular cancer arising from melanocytes within the uveal tract. UM has a high propensity to spread hematogenously to the liver, with up to 50% of patients developing liver metastases. Unfortunately, once liver metastasis occurs, patient prognosis is extremely poor with as few as 8% of patients surviving beyond two years. There are no standard-of-care therapies available for the treatment of metastatic UM, hence it is a clinical area of urgent unmet need. Here, the clinical relevance and therapeutic potential of cysteinyl leukotriene receptors (CysLT1 and CysLT2) in UM was evaluated. High expression of CYSLTR1 or CYSLTR2 transcripts is significantly associated with poor disease-free survival and poor overall survival in UM patients. Digital pathology analysis identified that high expression of CysLT1 in primary UM is associated with reduced disease-specific survival (p = 0.012; HR 2.76; 95% CI 1.21-6.3) and overall survival (p = 0.011; HR 1.46; 95% CI 0.67-3.17). High CysLT1 expression shows a statistically significant (p = 0.041) correlation with ciliary body involvement, a poor prognostic indicator in UM. Small molecule drugs targeting CysLT1 were vastly superior at exerting anti-cancer phenotypes in UM cell lines and zebrafish xenografts than drugs targeting CysLT2. Quininib, a selective CysLT1 antagonist, significantly inhibits survival (p < 0.0001), long-term proliferation (p < 0.0001), and oxidative phosphorylation (p < 0.001), but not glycolysis, in primary and metastatic UM cell lines. Quininib exerts opposing effects on the secretion of inflammatory markers in primary versus metastatic UM cell lines. Quininib significantly downregulated IL-2 and IL-6 in Mel285 cells (p < 0.05) but significantly upregulated IL-10, IL-1β, IL-2 (p < 0.0001), IL-13, IL-8 (p < 0.001), IL-12p70 and IL-6 (p < 0.05) in OMM2.5 cells. Finally, quininib significantly inhibits tumour growth in orthotopic zebrafish xenograft models of UM. These preclinical data suggest that antagonism of CysLT1, but not CysLT2, may be of therapeutic interest in the treatment of UM.

The Omentum in Obesity-Associated Cancer: A Hindrance to Effective Natural Killer Cell Migration towards Tumour Which Can Be Overcome by CX3CR1 Antagonism

Oesophagogastric adenocarcinomas (OAC) are obesity-associated malignancies, underpinned by severe immune dysregulation. We have previously shown that natural killer (NK) cells preferentially migrate to OAC omentum, where they undergo phenotypic and functional alterations and apoptosis. Furthermore, we have identified the CX3CR1:fractalkine (CX3CL1) pathway as pivotal in their recruitment to omentum. Here, we elucidate whether exposure to the soluble microenvironment of OAC omentum, and in particular fractalkine and IL-15 affects NK cell homing capacity towards oesophageal tumour. Our data uncover diminished NK cell migration towards OAC tumour tissue conditioned media (TCM) following exposure to omental adipose tissue conditioned media (ACM) and reveal that this migration can be rescued with CX3CR1 antagonist E6130. Furthermore, we show that fractalkine has opposing effects on NK cell migration towards TCM, when used alone or in combination with IL-15 and uncover its inhibitory effects on IL-15-mediated stimulation of death receptor ligand expression. Interestingly, treatment with fractalkine and/or IL-15 do not significantly affect NK cell adhesion to MAdCAM-1, despite changes they elicit to the expression of integrin α4β7. This study provides further evidence that CX3CR1 antagonism has therapeutic utility in rescuing NK cells from the deleterious effects of the omentum and fractalkine in OAC, thus limiting their dysfunction.

A qualitative meta-synthesis examining spirituality as experienced by individuals living with terminal cancer

This review aimed to examine and synthesise literature on spirituality as experienced by individuals living with terminal cancer. Six databases were systematically searched for studies with qualitative findings relevant to spirituality and terminal cancer. Thirty-seven studies were included and thematic synthesis was used to identify themes. Analytical themes included: making sense of dying; living with dying; feeling connected; and being reflective. This review highlights how the experience of spirituality can positively impact the lives of terminal cancer patients. Further, these findings suggest that spirituality can be a transformative experience that allows individuals to experience peace at end of life.

Real-time ex vivo monitoring of NK cell migration toward obesity-associated oesophageal adenocarcinoma following modulation of CX3CR1

Oesophagogastric adenocarcinomas (OAC) are poor prognosis, obesity-associated cancers which may benefit from natural killer (NK) cell-based immunotherapies. Cellular immunotherapies encounter two key challenges to their success in OAC, namely recruitment to extratumoural tissues such as the omentum at the expense of the tumour and an immunosuppressive tumour microenvironment (TME) which can hamper NK cell function. Herein, we examined approaches to overcome the detrimental impact of obesity on NK cells and NK cell-based immunotherapies. We have demonstrated that NK cells migrate preferentially to the chemotactic signals of OAC patient-derived omentum over tumour in an ex vivo model of immune cell migration. We have identified CX3CR1 modulation and/or tumour chemokine profile remodelling as approaches to skew NK cell migration towards tumour. We also report targetable immunosuppressive facets of the obese OAC TME which dampen NK cell function, in particular cytotoxic capabilities. These data provide insights into approaches to therapeutically overcome key challenges presented by obesity and will inform superior design of NK cell-based immunotherapies for OAC.

Expression of MxA in esophageal cancer cell lines can influence sensitivity to chemotherapeutic agents but this does not require apoptosis

Esophageal cancer is a poor prognosis cancer characterized by intrinsic or acquired resistance to chemotherapeutic agents. The primary determinants of treatment failure are unknown. Expression of an anti-viral protein, myxovirus resistance protein A (MxA) is de-regulated in many cancers, including esophageal cancer, and its activity has been linked to apoptosis. This study has assessed whether MxA expression can influence the response of esophageal cancer cells to the chemotherapeutic agents 5-fluorouracil (5-FU) or oxaliplatin. MxA protein was differentially expressed in a panel of five esophageal cancer cell lines. KYSE450 and KYSE140 cells did not express MxA and were apoptosis incompetent. FLO-1, KYSE270, and OE21 cells expressed MxA, were more drug-sensitive and were apoptosis competent. MxA was artificially overexpressed in cell lines with no endogenous expression (KYSE450 and KYSE140). This increased the resistance of KYSE450 but not KYSE140 cells. Both cell lines remained apoptosis incompetent. We then evaluated siRNA knockdown of MxA in FLO-1 cells and CRISPR knockout in OE21 cells. Knockdown of MxA significantly increased drug sensitivity and caspase-3 activation in FLO-1 cells. OE21-MX1KO cells were also more drug-sensitive, but in contrast to FLO-1 cells, caspase-3 activation was reduced. Collectively these data indicate that MxA can promote resistance to chemotherapy, but this does not always correspond with effects on apoptosis. Effects on apoptosis are cell line specific, suggesting that other co-operating pathways determine the overall impact of MxA. Importantly, in cancer cells that overexpress the protein, drug sensitivity can be improved by interfering with MxA.

Biomarkers of pembrolizumab efficacy in advanced anal squamous cell carcinoma: analysis of a phase II clinical trial and a cohort of long-term responders

BACKGROUND

Recent trials suggest that programmed cell death 1 (PD-1)-directed immunotherapy may be beneficial for some patients with anal squamous cell carcinoma and biomarkers predictive of response are greatly needed.

METHODS

This multicenter phase II clinical trial (NCT02919969) enrolled patients with metastatic or locally advanced incurable anal squamous cell carcinoma (n=32). Patients received pembrolizumab 200 mg every 3 weeks. The primary endpoint of the trial was objective response rate (ORR). Exploratory objectives included analysis of potential predictive biomarkers including assessment of tumor-associated immune cell populations with multichannel immunofluorescence and analysis of circulating tumor tissue modified viral-human papillomavirus DNA (TTMV-HPV DNA) using serially collected blood samples. To characterize the clinical features of long-term responders, we combined data from our prospective trial with a retrospective cohort of patients with anal cancer treated with anti-PD-1 immunotherapy (n=18).

RESULTS

In the phase II study, the ORR to pembrolizumab monotherapy was 9.4% and the median progression-free survival was 2.2 months. Despite the high level of HPV positivity observed with circulating TTMV-HPV DNA testing, the majority of patients had low levels of tumor-associated CD8+PD-1+ T cells on pretreatment biopsy. Patients who benefited from pembrolizumab had decreasing TTMV-HPV DNA scores and a complete responder's TTMV-HPV DNA became undetectable. Long-term pembrolizumab responses were observed in one patient from the trial (5.3 years) and three patients (2.5, 6, and 8 years) from the retrospective cohort. Long-term responders had HPV-positive tumors, lacked liver metastases, and achieved a radiological complete response.

CONCLUSIONS

Pembrolizumab has durable efficacy in a rare subset of anal cancers. However, despite persistence of HPV infection, indicated by circulating HPV DNA, most advanced anal cancers have low numbers of tumor-associated CD8+PD-1+ T cells and are resistant to pembrolizumab.

Chromosome 1 Alterations in Multiple Myeloma: Considerations for Precision Therapy

Multiple myeloma (MM) is an incurable blood malignancy characterized by the clonal expansion of plasma cells and the secretion of monoclonal immunoglobulins. High-risk MM, defined by specific cytogenetic abnormalities, poses significant therapeutic challenges and is associated with inferior survival outcomes compared to standard-risk disease. Although molecularly targeted therapies have shown efficacy in other hematologic malignancies, currently venetoclax is the only targeted therapy approved for MM (t(11;14)). However, chromosome 1q gains, amplifications, and 1p deletions are frequently observed in MM, and have been linked to drug resistance and poor patient prognosis. Accordingly, this review focuses on emerging MM precision therapies capable of targeting dysregulated genes within these regions. It addresses gene therapies, small molecule inhibitors and monoclonal antibodies currently under investigation to antagonize oncogenic drivers including MCL-1, BCL9, F11R, and CKS1B, all of which are implicated in cell survival, proliferation or drug resistance. In conclusion, the link between chromosome 1 abnormalities and high-risk disease in MM patients offers a compelling rationale to identify and explore therapeutic targeting of chromosome 1 gene products as a novel precision medicine approach for a poorly served patient population.

Perioperative systemic IL-6 and immune-adipose- metabolism transcription in tumour and tumour adjacent breast cancer

Surgical resection is the primary treatment approach for patients with breast cancer. Despite optimal multimodal treatment, metastatic recurrence remains a risk. Surgery-mediated systemic inflammation and local tissue inflammation generate an immunosuppressive and wound-healing environment that may accelerate cancer recurrence and metastasis post-operatively. Investigating the impact of surgery on local and systemic inflammation may provide knowledge for improvement of patient prognosis and treatment opportunities. Systemic cytokines were quantified in the blood plasma of patients with breast cancer pre-operatively, early post-operatively, and late post-operatively. Early post-operative levels of IL-6 were significantly elevated in patients who underwent mastectomy compared with wide local excision. Post-operative IL-6 levels correlate with clinicopathological features (age and BMI). The transcriptomes of local matched tumour and normal tumour adjacent (normal) breast tissue, from patients with breast cancer, were analysed by RNA-Seq. Elevated gene expressions of IL6, ADIPOQ, FABP4, LPL, PPARG, and CD36 in normal tissue were associated with worse overall survival of patients with ER-positive breast cancer. In tissue with higher expression of IL6 and ADIPOQ, a higher abundance of M2-like macrophage gene expression was identified. This study revealed perioperative systemic dynamics of inflammatory mediators and identified local immune-adipose-metabolism gene expression in tumour-adjacent tissue associated with pro-tumour function.

The impact of expanded access programs for systemic anticancer therapy in an Irish cancer centre

BACKGROUND

Expanded access programs (EAPs) allow cancer patients with unmet clinical need to obtain access to pre-authorisation treatments. There is no standardised process for implementing these programs nationally, and real-world data on their impact is lacking.

AIMS

This study aimed to evaluate the prevalence of such EAPs and their impact in a cancer centre.

METHODS

Data relating to adult cancer patients treated via EAPs from 2011 to 2021 in three Cork university hospitals was collated. Descriptive statistics were employed to get an overview of the impact these programs currently have on cancer care provision.

RESULTS

We identified 193 patients who accessed EAPs during the study period, availing of 33 separate drugs for a total of 50 different cancer indications. The prevalence of EAP usage was shown to have been trending upwards in recent years with a total of 189 programs being accessed throughout the period. Drugs provided were from a number of different anti-cancer drug classes, particularly targeted therapies (n = 18) and immune checkpoint inhibitors (n = 17). Cancers from a wide range of both solid and liquid tumour types were treated with EAP drugs, and patients treated were from across a broad spectrum of ages (26-82, SD 11.99).

CONCLUSIONS

EAPs have an increasing role in accessing novel cancer therapies in our community and by extension nationally. Equity of EAP access would be facilitated by a national registry of available agents which we have established. Assessment of their benefits and toxicities would be enhanced by the requirement for a real-world database as a condition of EAP approval.

Optimising oncology drug expenditure in Ireland

A combination of improvements in patient survival, increasing treatment duration, and the development of more expensive agents has led to a doubling of per-capita spending on cancer medicines in Ireland (2008-2018). Despite this, access to new drugs is poor in comparison to other EU countries. We examine methods to optimise oncology drug spending to facilitate access to newer anticancer agents. Key targets for spending optimisation (biosimilar use, clinical trials and expanded access programs, waste reduction, avoidance of futile treatment, and altered drug scheduling) were identified through an exploratory analysis. A structured literature search was performed, with a focus on articles relevant to the Irish Healthcare system, supplemented by reports from statutory bodies. At the present time, EMA-approved agents are available once approved by the NCPE. Optimising drug costs occurs through guideline-based practice and biosimilar integration, the latter provides €80 million in cost savings annually. Access to novel therapies can occur via over 50 clinical trials and 28 currently available expanded access programmes. Additional strategies include reversion to weight-based immunotherapy dosing, potentially saving €400,000 per year in our centre alone, vial sharing, and optimisation of treatment schedules. A variety of techniques are being employed by oncologists to optimise costs and increase access to innovation for patients. Use of biosimilars, drug wastage, and prescribing at end of life should be audited as key performance indicators, which may lead to reflective practice on treatment planning. Such measures could further optimise oncology drug expenditure nationally facilitating approval of new agents.