An unusual non‑metastatic, mismatch repair‑deficient primary gastric squamous cell carcinoma presenting as a large, exophytic, bleeding tumor: A case report

Primary gastric squamous cell carcinoma (GSCC) is an extremely rare malignancy with a poor prognosis. Despite the improved knowledge regarding its pathogenesis and biology, the treatment options remain limited. The present study reported on the unique case of a mismatch repair-deficient (dMMR) primary GSCC in a 79-year-old woman reporting fatigue and symptoms of upper gastrointestinal tract bleeding. Physical examination revealed abdominal pain at palpation. Gastroscopy revealed a large, exophytic, bleeding tumor. Medical imaging confirmed a mushroom-like polyp in the lumen of the stomach, with no signs of disease spread. Total gastrectomy and D2 lymphadenectomy were performed. Pathological examination of the post-operational material confirmed a well-differentiated SCC invading the mucosa, submucosa and muscle layer. There were no signs of dissemination observed in any of the 32 excised lymph nodes. Notably, according to the last follow-up, the patient remains well, supporting the 5-year GSCC survival rate statistics. To the best of our knowledge, this is the first such GSCC case reported in the Surgical Oncology Outpatient Clinic (Copernicus Memorial Hospital, Lodz, Poland) and these findings add to the limited data on GSCC. Although this is a very rare condition, it should always be considered during the process of diagnosis of gastric tumors.

Remission of Thymoma on Steroid Therapy in a Patient With Atypical Thymoma-Associated Multiorgan Autoimmunity: A Case Report and Literature Review

In up to 34% of cases, thymoma, itself a rare neoplasm, is accompanied by autoimmune disorders, two of which are thymoma-associated multiorgan autoimmunity (TAMA) and paraneoplastic autoimmune multiorgan syndrome (PAMS). Unfortunately, differential diagnosis between these two entities can be challenging since no strict PAMS definition exists and PAMS can overlap with a subgroup of TAMA patients with skin lesions as leading presentation. We present a case of a 68-year-old woman with a diagnosis of thymoma accompanied by myasthenia gravis, hypothyroidism and GvHD-like mucocutaneous lesions that initially could account to both TAMA and PAMS diagnosis. However, following the exclusion of humoral autoimmunity against components of epithelial cells junction, TAMA was finally established. Interestingly, the introduction of corticosteroid therapy for TAMA symptom management resulted in unexpected partial remission of thymoma with no impact on mucocutaneous lesions. Our case study is an example of two extremely rare phenomena accompanying thymomas: unprecedented TAMA presentation with GvHD-like mucositis, which as we postulate should be placed in the spectrum of TAMA, and tumor remission on steroids.

Leukemia Inhibitory Factor: A Potential Biomarker and Therapeutic Target in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive, treatment-resistant cancer. Five-year survival rate is about 9%, one of the lowest among all solid tumors. Such a poor outcome is partly due to the limited knowledge of tumor biology, and the resulting lack of effective treatment options and robust predictive biomarkers. The leukemia inhibitory factor (LIF) has recently emerged as a potential biomarker and therapeutic target for PDAC. Accumulating evidence has suggested that LIF plays a role in supporting cancer evolution as a regulator of cell differentiation, renewal and survival. Interestingly, it can be detected in the serum of PDAC patients at higher concentrations than healthy individuals, this supporting its potential value as diagnostic biomarker. Furthermore, preliminary data indicate that testing for LIF serum concentration or tissue expression may help with treatment response monitoring and prognostication. Finally, studies in PDAC mouse models have also shown that LIF may be a valuable therapeutic target, and first-in-human clinical trial is currently ongoing. This article aims to review the available data on the role of LIF in PDAC promotion, and to discuss the evidence supporting its potential role as a biomarker and target of effective anti-cancer therapy in this setting.

Gene expression of ASNS, LGMN and CTSB is elevated in a subgroup of childhood BCP-ALL with PAX5 deletion

Resistance to L-asparaginase (L-asp) is a major contributor to poor treatment outcomes of several subtypes of childhood B cell precursor acute lymphoblastic leukemia (BCP-ALL). Asparagine synthetase (ASNS), legumain (LGMN) and cathepsin B (CTSB) serve a key role in L-asp resistance. The association between genetic subtypes of BCP-ALL and the expression of ASNS, LGMN and CTSB may elucidate the mechanisms of treatment failure. Bone marrow samples of 52 children newly diagnosed with BCP-ALL were screened for major genetic abnormalities and ASNS, LGMN and CTSB gene expression levels. The cohort was further divided into groups corresponding to the key genetic aberrations occurring in BCP-ALL: Breakpoint cluster region and Abelson murine leukemia viral oncogene homolog 1 fusion; hyperdiploidy, hypodiploidy, ETS variant 6 and runt-related transcription factor 1 fusion and other BCP-ALL with no primary genetic aberration identified. A subgroup analysis based on the differences in copy number variations demonstrated a significant increase of ASNS, LGMN and CTSB median expression in other BCP-ALL cases with paired box 5 (PAX5) deletion (P=0.0117; P=0.0036; P<0.0001, respectively) compared with those with wild-type PAX5. Patients with high ASNS expression exhibited longer relapse-free survival (RFS) compared with those with low ASNS levels (P=0.0315; HR, 0.19; 95% CI, 0.04-0.86); the 5-year RFS for patients in the high ASNS expression group was 90.15% (95% CI, 87.90-92.40%). Despite the impact on ASNS, LGMN and CTSB expression, PAX5 deletion did not influence RFS in the other BCP-ALL group (P=0.6839). Therefore, the results of the present study revealed high levels of ASNS, LGMN and CTSB expression in the other BCP-ALL group with concomitant PAX5 deletion and no subsequent deterioration in 5-year RFS. High ASNS expression level, as a single factor, was strongly associated with an improved outcome.

MLPA as a complementary tool for diagnosis of chromosome 21 aberrations in childhood BCP-ALL

Chromosome 21 abnormalities are the most frequent genetic findings in childhood B cell precursor acute lymphoblastic leukemia (BCP-ALL) cases. Majority of patients are effectively diagnosed with fluorescence in situ hybridization (FISH) and karyotyping; however, some cases may require additional tools to be used. Bone marrow samples of 373 childhood BCP-ALL patients were tested for chromosome 21 copy number variations (CNVs) with Multiplex Ligation-dependent Probe Amplification (MLPA) P327 array. Results from MLPA and cytogenetics were compared between groups according to the type of abnormality found on chromosome 21. Out the group of 235 patients, chromosome 21 multiplication was found by FISH assay in 56 cases (23.81%), ETV6-RUNX1 fusion in 34 (14.47%) and iAMP21 in 3 (1.28%) children, remaining 142 (60.43%) patients had no known chromosome 21 aberration. Median peak ratios of all tested probes in MLPA in aforementioned groups were 1.47 (IQR 1.28-1.77) vs. 1.00 (IQR 1.00-1.09) vs. 2.79 (IQR 1.97-2.83) vs. 1.00 (1.00-1.11), respectively. Aforementioned peak ratio of ETV6-RUNX1 fusion group was similar with patients of no known chromosome 21 aberration (p = 0.71). Interestingly, both groups differed from patients with chromosome 21 multiplication (p < 10-5) and with iAMP21 (p < 10-5). All cases of iAMP21 were correctly recognized by MLPA. MLPA seems to be good additional tool in the diagnostic process of chromosome 21 CNVs, especially in cases with iAMP21.

Born-Oppenheimer Molecular Dynamics Study on Proton Dynamics of Strong Hydrogen Bonds in Aspirin Crystals, with Emphasis on Differences between Two Crystal Forms

In this study, the proton dynamics of hydrogen bonds for two forms of crystalline aspirin was investigated by the Born-Oppenheimer molecular dynamics (BOMD) method. Analysis of the geometrical parameters of hydrogen bonds using BOMD reveals significant differences in hydrogen bonding between the two crystalline forms of aspirin, Form I and Form II. Analysis of the trajectory for Form I shows spontaneous proton transfer in cyclic dimers, which is absent in Form II. Quantization of the O-H stretching modes allows a detailed discussion on the strength of hydrogen-bonding interactions. The focal point of our study is examination of the hydrogen bond characteristics in the crystal structure and clarification of the influence of hydrogen bonding on the presence of the two crystalline forms of aspirin. In the BOMD method, thermal motions were taken into account. Solving the Schrödinger equation for the snapshots of 2D proton potentials, extracted from MD, gives the best agreement with IR spectra. The character of medium-strong hydrogen bonds in Form I of aspirin was compared with that of weaker hydrogen bonds in aspirin Form II. Two proton minima are present in the potential function for the hydrogen bonds in Form I. The band contours, calculated by using one- and two-dimensional O-H quantization, reflect the differences in the hydrogen bond strengths between the two crystalline forms of aspirin, as well as the strong hydrogen bonding in the cyclic dimers of Form I and the medium-strong hydrogen bonding in Form II.

The Stricter the Better? The Relationship between Targeted HbA1c Values and Metabolic Control of Pediatric Type 1 Diabetes Mellitus

INTRODUCTION

It remains unclear how HbA1c recommendations influence metabolic control of paediatric patients with type 1 diabetes mellitus. To evaluate this we compared reported HbA1c with guideline thresholds.

MATERIALS AND METHODS

We searched systematically MEDLINE and EMBASE for studies reporting on HbA1c in children with T1DM and grouped them according to targeted HbA1c obtained from regional guidelines. We assessed the discrepancies in the metabolic control between these groups by comparing mean HbA1c extracted from each study and the differences between actual and targeted HbA1c.

RESULTS

We included 105 from 1365 searched studies. The median (IQR) HbA1c for the study population was 8.30% (8.00%-8.70%) and was lower in "6.5%" than in "7.5%" as targeted HbA1c level (8.20% (7.85%-8.57%) versus 8.40% (8.20%-8.80%); p = 0.028). Median difference between actual and targeted HbA1c was 1.20% (0.80%-1.70%) and was higher in "6.5%" than in "7.5%" (1.70% (1.30%-2.07%) versus 0.90% (0.70%-1.30%), resp.; p < 0.001).

CONCLUSIONS

Our study indicates that the 7.5% threshold results in HbA1c levels being closer to the therapeutic goal, but the actual values are still higher than those observed in the "6.5%" group. A meta-analysis of raw data from national registries or a prospective study comparing both approaches is warranted as the next step to examine this subject further.

Transient protein states in designing inhibitors of the MDM2-p53 interaction

Reactivation of p53 by release of the functional protein from its inhibition by MDM2 provides an efficient, nongenotoxic approach to a wide variety of cancers. We present the cocrystal structures of two complexes of MDM2 with inhibitors based on 6-chloroindole scaffolds. Both molecules bound to a distinct conformational state of MDM2 with nM-μM affinities. In contrast to other structurally characterized antagonists, which mimic three amino acids of p53 (Phe19, Trp23, and Leu26), the compounds induced an additional hydrophobic pocket on the MDM2 surface and unveiled a four-point binding mode. The enlarged interaction interface of the inhibitors resulted in extension of small molecules binding toward the "lid" segment of MDM2 (residues 19-23)--a nascent element that interferes with p53 binding. As supported by protein engineering and molecular dynamics studies, employing these unstable elements of MDM2 provides an efficient and yet unexplored alternative in development of MDM2-p53 association inhibitors.