Modulation of cAMP/cGMP signaling as prevention of congenital heart defects in Pde2A deficient embryos: a matter of oxidative stress

Phosphodiesterase 2A (Pde2A) is a dual-specific PDE that breaks down both cAMP and cGMP cyclic nucleotides. We recently highlighted a direct relationship between Pde2A impairment, a consequent increase of cAMP, and the appearance of mouse congenital heart defects (CHDs). Here we aimed to characterize the pathways involved in the development of CHDs and in their prevention by pharmacological approaches targeting cAMP and cGMP signaling. Transcriptome analysis revealed a modulation of more than 500 genes affecting biological processes involved in the immune system, cardiomyocyte development and contractility, angiogenesis, transcription, and oxidative stress in hearts from Pde2A-/- embryos. Metoprolol and H89 pharmacological administration prevented heart dilatation and hypertabeculation in Pde2A-/- embryos. Metoprolol was also able to partially impede heart septum defect and oxidative stress at tissue and molecular levels. Amelioration of cardiac defects was also observed by using the antioxidant NAC, indicating oxidative stress as one of the molecular mechanisms underpinning the CHDs. In addition, Sildenafil treatment recovered cardiac defects suggesting the requirement of cAMP/cGMP nucleotides balance for the correct heart development.

Retinoic acid and proteotoxic stress induce AML cell death overcoming stromal cell protection

BACKGROUND

Acute myeloid leukemia (AML) patients bearing the ITD mutation in the tyrosine kinase receptor FLT3 (FLT3-ITD) present a poor prognosis and a high risk of relapse. FLT3-ITD is retained in the endoplasmic reticulum (ER) and generates intrinsic proteotoxic stress. We devised a strategy based on proteotoxic stress, generated by the combination of low doses of the differentiating agent retinoic acid (R), the proteasome inhibitor bortezomib (B), and the oxidative stress inducer arsenic trioxide (A).

METHODS

We treated FLT3-ITD+ AML cells with low doses of the aforementioned drugs, used alone or in combinations and we investigated the induction of ER and oxidative stress. We then performed the same experiments in an in vitro co-culture system of FLT3-ITD+ AML cells and bone marrow stromal cells (BMSCs) to assess the protective role of the niche on AML blasts. Eventually, we tested the combination of drugs in an orthotopic murine model of human AML.

RESULTS

The combination RBA exerts strong cytotoxic activity on FLT3-ITD+ AML cell lines and primary blasts isolated from patients, due to ER homeostasis imbalance and generation of oxidative stress. AML cells become completely resistant to the combination RBA when treated in co-culture with BMSCs. Nonetheless, we could overcome such protective effects by using high doses of ascorbic acid (Vitamin C) as an adjuvant. Importantly, the combination RBA plus ascorbic acid significantly prolongs the life span of a murine model of human FLT3-ITD+ AML without toxic effects. Furthermore, we show for the first time that the cross-talk between AML and BMSCs upon treatment involves disruption of the actin cytoskeleton and the actin cap, increased thickness of the nuclei, and relocalization of the transcriptional co-regulator YAP in the cytosol of the BMSCs.

CONCLUSIONS

Our findings strengthen our previous work indicating induction of proteotoxic stress as a possible strategy in FLT3-ITD+ AML therapy and open to the possibility of identifying new therapeutic targets in the crosstalk between AML and BMSCs, involving mechanotransduction and YAP signaling.

Understanding ER homeostasis and the UPR to enhance treatment efficacy of acute myeloid leukemia

Protein biogenesis, maturation and degradation are tightly regulated processes that are governed by a complex network of signaling pathways. The endoplasmic reticulum (ER) is responsible for biosynthesis and maturation of secretory proteins. Circumstances that alter cellular protein homeostasis, determine accumulation of misfolded and unfolded proteins in the ER, a condition defined as ER stress. In case of stress, the ER activates an adaptive response called unfolded protein response (UPR), a series of pathways of major relevance for cancer biology. The UPR plays a preeminent role in adaptation of tumor cells to the harsh conditions that they experience, due to high rates of proliferation, metabolic abnormalities and hostile environment scarce in oxygen and nutrients. Furthermore, the UPR is among the main adaptive cell stress responses contributing to the development of resistance to drugs and chemotherapy. Clinical management of Acute Myeloid Leukemia (AML) has improved significantly in the last decade, thanks to development of molecular targeted therapies. However, the emergence of treatment-resistant clones renders the rate of AML cure dismal. Moreover, different cell populations that constitute the bone marrow niche recently emerged as a main determinant leading to drug resistance. Herein we summarize the most relevant literature regarding the role played by the UPR in expansion of AML and ability to develop drug resistance and we discuss different possible modalities to overturn this adaptive response against leukemia. To this aim, we also describe the interconnection of the UPR with other cellular stress responses regulating protein homeostasis. Finally, we review the newest findings about the crosstalk between AML cells and cells of the bone marrow niche, under physiological conditions and in response to therapies, discussing in particular the importance of the niche in supporting survival of AML cells by favoring protein homeostasis.

1542 An Audit of Rates of Lynch Testing in Confirmed Colorectal Cancer Cases

Introduction

12% of cancers in the UK are colorectal in origin1 with 1-3% secondary to genetic mismatch repair due to Lynch syndrome2, for which the 2017 NICE guidance recommended that patients with colorectal cancer (CRC) be tested3. It increases the risk of developing other cancers such as endometrial, ovarian and small bowel1, changes the oncological treatment offered to CRC patients4,5, and prompts investigation of their relatives for the condition. In this audit we assessed our rates of trust wide Lynch testing.

Method

Patients with a diagnosis of CRC from 2017-2019 were identified from records held by our cancer services department. Histology results were obtained from an online results portal.

Results

345 were included in the analysis, 79% of which were tested for Lynch, with time taken from biopsy to results ranging from 2 to 276 days (average 45). 54% had results within 30 days, 34% between 30 and 90 days and 12% exceeded 90 days. There was no significant difference of Lynch testing rates between each year. The proportion of results returned within 30 days increased by year, with rates of 30% (2017), 55% (2018) and 71% (2019). The median days from biopsy to results also improved, from 39 to 28 and 16 days, respectively.

Conclusions

Rates and efficiency of our screening for lynch syndrome need improvement to meet the target suggested by NICE. The impact of the recent centralisation our regions pathology department on Lynch testing service provision requires further investigation.

698 A Systematic Review of Smartphone Applications for Enhanced Recovery After Surgery (ERAS) Following Colorectal Surgery

Introduction

Length of stay (LOS) following colorectal surgery has reduced due to enhanced recovery after surgery (ERAS) programs. Telemedicine has shown potential for patients to remotely access support, communicate progress with their medical team and enhance patient empowerment. We conducted a systematic review of smartphone applications for ERAS following colorectal surgery measuring patient outcomes and experience.

Method

The review was performed adhering to PRISMA guidelines, using search terms pertaining to ERAS, colorectal surgery, and mobile applications via electronic databases. All peer-reviewed English articles were assessed for inclusion and quality by two reviewers. A qualitative analysis was conducted to evaluate methodologies, patient experience, and outcomes.

Results

206 abstracts were identified from which 5 articles (2 RCTs and 3 cohorts) were included in the analysis. Studies surveyed patient adherence to ERAS, LOS, readmission, intra and postoperative complications. Four studies recorded patient satisfaction, whilst one assessed quality of life and application validation.

Conclusions

The review highlights paucity in the use of smartphone applications after ERAS in colorectal surgery but demonstrates high patient satisfaction levels. Service delivery in the NHS has increasingly moved to a virtual platform during the coronavirus pandemic. More research and engagement in the development and use of smartphone applications would enhance care for patients.

Physiological changes after colorectal surgery suggest that anastomotic leakage is an early event: a retrospective cohort study

AIM

Anastomotic leakage (AL) is often identified 7-10 days after colorectal surgery. However, in retrospect, abnormalities may be evident much earlier. This study aims to identify the clinical time point when AL occurs.

METHOD

This is a retrospective case-matched cohort comparison study, assessing patients undergoing left-sided colorectal resection between 2006 and 2015 at a specialist colorectal unit. Patients who developed AL (LEAK) were case-matched to two CONTROL patients by procedure, gender, laparoscopic modality and diverting stoma. Case note review allowed the collection of basic observation data and blood tests (leukocyte count, C-reactive protein, bilirubin, alanine transaminase, creatinine) up to postoperative day (POD) 4. The cohorts were compared, with the main outcome measure being changes in basic observation data.

RESULTS

Of 554 patients, 49 developed AL. These were matched to 98 CONTROL patients. Notes were available for 105 patients (32 LEAK/73 CONTROL). Groups were similar in demographics, tumour or nodal status, preoperative radiotherapy, intra-operative air-leak integrity and drain usage. AL was detected clinically at a median of 7.5 days postoperatively. There was a significantly increased heart rate by the evening on POD 1 in LEAK patients (82.8 ± 14.2/min vs 75.1 ± 12.7/min, P = 0.0081) which persisted for the rest of the study. By POD 3, there was a significant increase in respiratory rate (18.0 ± 4.2/min vs 16.5 ± 1.3/min, P = 0.0069) and temperature (37.0 ± 0.4C vs 36.7 ± 0.3C, P = 0.0006) in LEAK patients. C-reactive protein was significantly higher in LEAK patients from POD 2 (165 ± 95 mg/l vs 121 ± 75 mg/l, P = 0.023).

CONCLUSIONS

Physiological and biochemical changes associated with AL happen very early postoperatively, suggesting that AL may occur within 36 h after surgery, despite much later clinical detection.

Acinic cell carcinoma of the breast: review of the literature

INTRODUCTION

The breast and salivary gland tissue share embryologic and thus pathological similarities. Acinic cell carcinoma (ACC) is a typical tumor in salivary glands, but rarely arises in breast too. We reviewed 38 cases of mammary ACC reported in literature and our case, the first ACC born within a fibroadenoma.

MATERIALS AND METHODS

Data were collected by a research for the key words acinic cell carcinoma breast on Pubmed in March 2014, including a case treated in our department. All reviewed cases were compared for clinical approach and histological pattern.

RESULTS

To date 23 articles presenting cases of ACC of the breast are reported in literature. We included in our review 38 cases previously described and one new case. The histological pattern was predominantly solid with a microglandular structure. All the tumor cells were cytologically characterized by monotonous round cells with a finely granular, weakly eosinophilic, or clearly vacuolated cytoplasm. The most of the cells were intensely stained with anti-lysozime, anti-amylase, anti-α1-chimotripsin, anti-EMA and anti-S100 protein antisera. Immunohistochemistry was also performed to point out: estrogen receptor (ER), progesterone receptor (PR), androgen receptors (AR), human epidermal growth factor receptor 2 overexpression (HER2/neu), E-cadherin (E-cad), cytokeratin-7 (CK7), gross cystic disease fluid protein 15 (GCDFP15), smooth muscle actin (SMA).

CONCLUSION

ACC of the breast is a rare tumor, showing similarities with the salivary gland counterpart, above all in terms of good prognosis, and differences from the ordinary invasive breast carcinoma. Further investigations are needed to elucidate the true histogenesis and the correct treatment.

Transient Facial Nerve Paralysis After Mandibular Sagittal Osteotomy

Facial nerve injuries are rare complications after orthognathic surgery. A literature review shows that such damages can develop with various mechanisms and are usually transient. Two cases of delayed facial paralysis after mandibular osteotomy with spontaneous recovery are reported.