PARP Inhibitors in Breast Cancer: a Short Communication.

PURPOSE OF REVIEW: In the last decade, poly (ADP-ribose) polymerase (PARP) inhibitors have been approved in the treatment of several cancers, such as breast and ovarian cancer. This article aims to discuss the current uses, limitations, and future directions for PARP inhibitors (PARPis) in the treatment of breast cancer. RECENT FINDINGS: Following the results of the OlympiAD and EMBRACA trials, PARPis were approved in HER2-negative breast cancer with a germline BRCA mutation. We reviewed this class of drugs' mechanism of action, efficacy, and limitations, as well as further studies that discussed resistance, impaired homologous recombination repair (HRR), and the combination of PARPis with other drugs. Improving understanding of HRR, increasing the ability to target resistance, and combining PARPis with other novel agents are continuing to increase the clinical utility of PARPis.

Validation and comparison of two new scoring systems for the prediction of complicated versus uncomplicated appendicitis.

OBJECTIVES: To validate the Atema and APSI scoring systems in the diagnosis of complicated vs uncomplicated appendicitis. To compare these scoring systems with computed tomography (CT) imaging alone to establish which method provides most accurate prediction of complicated vs uncomplicated appendicitis. METHODS: This was a retrospective review of a sample of 160 patients that underwent appendicectomy and CT imaging for suspected appendicitis between 2018 and 2021 in a tertiary university teaching hospital. Each scoring system was applied to all patients and results analysed and compared with the effectiveness of CT imaging, RESULTS: 32.5% (n = 52) were found to have complicated appendicitis and 67.5% (n = 108) uncomplicated appendicitis. Application of the Atema score to our cohort of patients resulted in a sensitivity 76.9% [CI (64.2, 87.5), specificity 58.7% [CI (48.9, 68.1)], PPV 47.1% [CI (40.5, 53.8) and NPV 84.2% [CI (76.0, 89.9)]. By comparison, the APSI yielded a sensitivity 50.9% [CI (36.6, 65.4)], specificity 76.1% [CI (67.0, 87.8)], PPV 50% [CI (39.2, 60.6)] and NPV 76% [CI (71.1, 81.7)]. Radiology prediction of complicated vs uncomplicated appendicitis with CT imaging showed sensitivity 46% [CI (32.2, 60.5)], specificity 79%; [CI (69.8, 86)], PPV 51% [CI (39.6, 62.5)] and NPV 75% [CI (69.8, 79.9)]. CONCLUSION: By comparing the APSI and Atema et al. scoring systems with CT reporting in our hospital, it appears that the Atema may confer some benefit in stratifying patient risk of complicated versus uncomplicated appendicitis. Further larger scale prospective studies are required.

Efficacy and Safety of Trastuzumab Deruxtecan in Breast Cancer: A Systematic Review and Meta-Analysis.

Trastuzumab deruxtecan (T-DXd) is a novel antibody-drug-conjugate (ADC), primarily used in the treatment of HER2-positive breast cancer. This study aimed to conduct a systematic review to evaluate the efficacy and safety of T-DXd in treating breast cancer, based on clinical trials. A systematic search of the literature was conducted to identify clinical trials investigating the efficacy and safety of T-DXd in breast cancer. Clinical trials of any phase were included. Outcome measures were any adverse events and survival. Meta-analysis was conducted where possible. Pooled prevalence for each adverse event of any grade and grade 3 or greater were estimated. Progression-free survival (PFS), overall survival (OS) and objective response rates (ORRs) were also reported to evaluate the efficacy of T-DXd in breast cancer. A total of 1593 patients from 6 clinical trials were included. Common adverse events of any grade were nausea, anemia, neutropenia, vomiting, fatigue, constipation and diarrhea, occurring in greater than 30% of cases. In terms of adverse events of grade 3 or more, only anemia and neutropenia occurred at a relatively high rate. Median PFS ranged from 11.1 to 22.1 months. There was evidence of a benefit of T-DXd compared to controls in terms of both PFS (OR: 0.38; 95% CI: 0.32, 0.45) and OS (OR: 0.61; 95% CI: 0.48, 0.78). ORRs ranged from 37% to 79.9%. The present systematic review shows evidence that T-DXd is a safe and effective agent in the treatment of breast cancer based on currently available data. The most common adverse events affected the blood, lymphatic and gastrointestinal systems. Interstitial lung disease (ILD) is a notable and potentially serious adverse event.

Assessing Mode of Recurrence in Breast Cancer to Identify an Optimised Follow-Up Pathway: 10-Year Institutional Review.

BACKGROUND: Breast cancer surveillance programmes ensure early identification of recurrence which maximises overall survival. Programmes include annual clinical examination and radiological assessment. There remains debate around the value of annual clinical exam in diagnosing recurrent disease/second primaries. The aim was to assess diagnostic modalities for recurrent breast cancer with a focus on evaluating the role of annual clinical examination. PATIENTS AND METHODS: A prospectively maintained database from a symptomatic breast cancer service between 2010-2020 was reviewed. Patients with biopsy-proven recurrence/second breast primary were included. The primary outcome was the diagnostic modality by which recurrences/secondary breast cancers were observed. Diagnostic modalities included (i) self-detection by the patient, (ii) clinical examination by a breast surgeon or (iii) radiological assessment. RESULTS: A total of 233 patients were identified and, following application of exclusion criteria, a total of 140 patients were included. A total of 65/140 (46%) patients were diagnosed clinically, either by self-detection or clinical examination, while 75/140 (54%) were diagnosed radiologically. A total of 59/65 (91%) of patients clinically diagnosed with recurrence presented to the breast clinic after self-detection of an abnormality. Four (6%) patients had cognitive impairment and recurrence was diagnosed by a carer. Two (3%) patients were diagnosed with recurrence by a breast surgeon at clinical examination. The median time to recurrence in all patients was 48 months (range 2-263 months). CONCLUSION: Clinical examination provides little value in diagnosing recurrence (< 5%) and surveillance programmes may benefit from reduced focus on such a modality. Regular radiological assessment and ensuring patients have urgent/easy access to a breast clinic if they develop new symptoms/signs should be the focus of surveillance programmes.

Review of the status of neoadjuvant therapy in HER2-positive breast cancer.

Purpose: The development of human epidermal growth factor receptor 2 (HER2)-directed therapies has revolutionized the treatment of HER2-positive breast cancer. The aim of this article is to review the continually evolving treatment strategies in the neoadjuvant setting of HER2-positive breast cancer, as well as the current challenges and future perspectives. Methods: Searches were undertaken on PubMed and Clinicaltrials.gov for relevant publications and trials. Findings: The current standard of care in high-risk HER2-positive breast cancer is to combine chemotherapy with dual anti-HER2 therapy, for a synergistic anti-tumor effect. We discuss the pivotal trials which led to the adoption of this approach, as well as the benefit of these neoadjuvant strategies for guiding appropriate adjuvant therapy. De-escalation strategies are currently being investigated to avoid over treatment, and aim to safely reduce chemotherapy, while optimizing HER2-targeted therapies. The development and validation of a reliable biomarker is essential to enable these de-escalation strategies and personalization of treatment. In addition, promising novel therapies are currently being explored to further improve outcomes in HER2-positive breast cancer.

Host Subtraction, Filtering and Assembly Validations for Novel Viral Discovery Using Next Generation Sequencing Data.

The use of next generation sequencing (NGS) to identify novel viral sequences from eukaryotic tissue samples is challenging. Issues can include the low proportion and copy number of viral reads and the high number of contigs (post-assembly), making subsequent viral analysis difficult. Comparison of assembly algorithms with pre-assembly host-mapping subtraction using a short-read mapping tool, a k-mer frequency based filter and a low complexity filter, has been validated for viral discovery with Illumina data derived from naturally infected liver tissue and simulated data. Assembled contig numbers were significantly reduced (up to 99.97%) by the application of these pre-assembly filtering methods. This approach provides a validated method for maximizing viral contig size as well as reducing the total number of assembled contigs that require down-stream analysis as putative viral nucleic acids.

Metagenomic study of the viruses of African straw-coloured fruit bats: detection of a chiropteran poxvirus and isolation of a novel adenovirus.

Viral emergence as a result of zoonotic transmission constitutes a continuous public health threat. Emerging viruses such as SARS coronavirus, hantaviruses and henipaviruses have wildlife reservoirs. Characterising the viruses of candidate reservoir species in geographical hot spots for viral emergence is a sensible approach to develop tools to predict, prevent, or contain emergence events. Here, we explore the viruses of Eidolon helvum, an Old World fruit bat species widely distributed in Africa that lives in close proximity to humans. We identified a great abundance and diversity of novel herpes and papillomaviruses, described the isolation of a novel adenovirus, and detected, for the first time, sequences of a chiropteran poxvirus closely related with Molluscum contagiosum. In sum, E. helvum display a wide variety of mammalian viruses, some of them genetically similar to known human pathogens, highlighting the possibility of zoonotic transmission.

A viral discovery methodology for clinical biopsy samples utilising massively parallel next generation sequencing.

Here we describe a virus discovery protocol for a range of different virus genera, that can be applied to biopsy-sized tissue samples. Our viral enrichment procedure, validated using canine and human liver samples, significantly improves viral read copy number and increases the length of viral contigs that can be generated by de novo assembly. This in turn enables the Illumina next generation sequencing (NGS) platform to be used as an effective tool for viral discovery from tissue samples.

Fibroblast-mediated delivery of GDNF induces neuronal-like outgrowth in PC12 cells.

HYPOTHESIS: Recombinantly modified cells deliver neurotrophic factors with the capacity to induce differentiation and the outgrowth of neurites of rat pheochromocytoma cells 12 (PC12) serving as a neuronal model. BACKGROUND: The benefit of cochlea implant (CI) is depending, among other factors, on the number of surviving spiral ganglion neurons (SGN). Studies have shown that the external application of neurotrophic factors in combination with electrical stimulation increases the survival rate of SGN after ototrauma. Therefore, functionalization of electrodes with recombinantly modified cells providing neurotrophic factors to the SGN for inducing survival mechanisms may be an approach to realize drug delivery to the cochlea. METHODS: Murine NIH3T3 cells were recombinantly modified with an infectious lentiviral monocistronic and bicistronic system to synthesize glial cell line-derived neurotrophic factor and the green fluorescent protein. Free glial cell line-derived neurotrophic factor from the supernatant of the modified NIH3T3 cells was added to rat PC12, and the neuronal-like outgrowth was determined for 10 days. RESULTS: A significant neuronal-like outgrowth appeared as early as Day 3 after the application of the supernatant. CONCLUSION: The results indicate that the established in vitro model represents a powerful basic model for determining signal pathways between neuronal-like processing PC12 cells and cellular drug delivery systems.

Engineering stem cells for therapy.

The differentiation of a stem cell is dependent on the environmental cues that it receives and can be modulated by the expression of different master regulators or by secreted factors or inducers. The use of genetically modified stem cells to express the required factors can direct differentiation along the requisite pathway. This approach to the engineering of stem cells is important, as control of the pluripotentiality of stem cells is necessary in order to avoid unwanted growth, migration or differentiation to nontarget tissues. The authors provide an overview of the stem cell engineering field, highlighting challenges and solutions, and focusing on recent developments in therapeutic applications in areas such as autoimmunity, CNS lesions, bone and joint diseases, cancer and myocardial infarction.

Clustering of immunoreceptor tyrosine-based activation motif-containing signalling subunits in CD4(+) T cells is an optimal signal for IFN-gamma production, but not for the production of IL-4.

CD4(+) T cells with pre-defined MHC-unrestricted specificity to type II collagen (CII) were engineered for cell-based anti-inflammatory gene therapy of autoimmune arthritis. To this end, recombinant chimeric immunoreceptors, C2gamma or C2zeta, were expressed in primary mouse keyhole limpet hemocyanin (KLH)-specific T(h)1 and T(h)2 cells using retrovirus vector-based somatic cell gene transfer. The ectodomain of these tyrosine-based activation motif (ITAM)-containing immunoreceptors is a single-chain IgG variable domain of an anti-CII mAb. The engineered cells might arrest migration when they encounter CII in articular cartilage. Up to 19 and 55% of transduced CD4(+) T cells expressed respectively C2gamma and C2zeta. The expression of C2gamma or C2zeta on the surface of CD4(+) T cells was down-regulated upon binding CII, and cells activated in such a way proliferated, up-regulated CD25 expression and produced cytokines. Comparison of cytokine levels normalized by the number of producer cells revealed that C2gamma and C2zeta were as potent as TCR in the induction of IFN-gamma, but induced lower levels of IL-4. It appears that the reason why CD4(+) T cells stimulated through C2gamma and C2zeta produce low levels of IL-4 is a lack of integration between co-stimulatory signals required for the optimal production of this cytokine and the ITAM-dependent signals generated by the immunoreceptors. The significance of these data for the development of anti-inflammatory gene therapy based on CD4(+) T cells targeted to a tissue-specific protein is discussed.

Highly efficient gene transfer into antigen-specific primary mouse lymphocytes with replication-deficient retrovirus expressing the 10A1 envelope protein.

BACKGROUND: Introduction of recombinant genes in the genome of primary lymphocytes by virtue of a replication-deficient retrovirus can be used in immunological studies and for cell-based gene therapy. METHODS: Packaging cells GP+E86 producing replication-deficient retrovirus incorporating the genes of enhanced green fluorescent protein (eGFP), C2gamma or C2xi, were generated by calcium phosphate-mediated transfection. Clones with the highest titres of retrovirus vector were isolated from them and their supernatants were used for transduction of PT67 cells. Primary mouse lymphocytes and T-cell hybridoma MD.45 were transduced by centrifugation with retroviral stock. The retroviral content of packaging cell supernatants was determined by dot blotting and hybridization with a DNA probe. RESULTS: PT67 cells produced approximately 50 times more retrovirus vector than the original GP+E86 clones. When retroviral stocks of PT67 and GP+E86 cells were used at 1/50 dilution and undiluted, respectively (to normalize them for retroviral RNA content), the transduction efficiency of mouse T-cell hybridoma was 40% and 5%, respectively. Centrifugation of target cells with retroviral stock at 2000 g for 60 min increased the percentage of transduced cells two- to three-fold. Within a population of cells isolated from the draining lymph nodes of an immunized mouse and reactivated with an antigen, up to 60% of CD4(+) T cells and up to 80% of B cells could be transduced with a transgene in replication-deficient retrovirus packaged by PT67 cells using the optimized gene transfer protocol. CONCLUSIONS: This protocol allows for the generation of packaging cells producing high titres of retrovirus vector. The 10A1 envelope protein is superior to the ecotropic one for the transduction of mouse lymphocytes.