Novel phase I study combining G1 phase, S phase, and G2/M phase cell cycle inhibitors in patients with advanced malignancies

Deep response to a combination of mTOR inhibitor temsirolimus and dual immunotherapy of nivolumab/ipilimumab in poorly differentiated thyroid carcinoma with PTEN mutation: a case report and literature review

Treating advanced thyroid cancer presents challenges due to its resistance to various treatment modalities, thereby limiting therapeutic options. To our knowledge, this study is the first to report the efficacy of temsirolimus in conjunction with dual immunotherapy of nivolumab/ipilimumab to treat heavily treated advanced PDTC. A 50-year-old female initially presented with a rapidly enlarging mass on her right neck. Subsequent diagnosis revealed poorly differentiated thyroid carcinoma, leading to a total thyroidectomy followed by post-operative radioablation therapy. After four years, an examination for persistent cough revealed a recurrence of the disease within multiple mediastinal nodes. Genetic analysis of blood samples uncovered somatic mutations in the tumor, specifically involving PTEN and TP53. The disease progressed despite palliative radiation, lenvatinib, and nivolumab/ipilimumab therapy. Consequently, temsirolimus, functioning as an mTOR inhibitor, was introduced as an adjunct to the nivolumab/ipilimumab regimen. This combination approach yielded remarkable clinical improvement and disease control for a duration of approximately six months. Temsirolimus likely suppressed the aberrantly activated PI3K/AKT/mTOR signaling pathway, facilitated by the PTEN genetic alteration, thus engendering an effective treatment response. This synergy between targeted agents and immunotherapy presents a promising therapeutic strategy for advanced PDTC patients with limited treatment alternatives. In previous clinical trials, mTOR inhibitors have demonstrated the ability to maintain stable disease (SD) in 65% to 74% for advanced thyroid cancer patients, including those with PDTC. When combined with other targeted therapies, the observed SD or partial response rates range from 80% to 97%. Many of these trials primarily involved differentiated thyroid carcinoma, with diverse genetic mutations. Thyroid cancer patients with alterations in the PI3K/mTOR/Akt appeared to benefit most from mTOR inhibitors. However, no clear association between the efficacy of mTOR inhibitors and specific histologies or genetic mutations has been established. Future studies are warranted to elucidate these associations.

Leukocyte subtype classification with multi-model fusion

Accurate classification of leukocytes is crucial for the diagnosis of hematologic malignancies, particularly leukemia. However, traditional leukocyte classification methods are time-consuming and subject to subjective interpretation by examiners. To address this issue, we aimed to develop a leukocyte classification system capable of accurately classifying 11 leukocyte classes, which would aid radiologists in diagnosing leukemia. Our proposed two-stage classification scheme involved a multi-model fusion based on ResNet for rough leukocyte classification, which focused on shape features, followed by fine-grained leukocyte classification using support vector machine for lymphocytes based on texture features. Our dataset consisted of 11,102 microscopic leukocyte images of 11 classes. Our proposed method achieved accurate leukocyte subtype classification with high levels of accuracy, sensitivity, specificity, and precision of 97.03 ± 0.05, 96.76 ± 0.05, 99.65 ± 0.05, and 96.54 ± 0.05, respectively, in the test set. The experimental results demonstrate that the leukocyte classification model based on multi-model fusion can effectively classify 11 leukocyte classes, providing valuable technical support for enhancing the performance of hematology analyzers.

Absence of terminal deoxynucleotidyl transferase expression in T-ALL/LBL accumulates chromosomal abnormalities to induce drug resistance

T-acute lymphoblastic leukemia/lymphoma (T-ALL/LBL) is a malignant neoplasm of immature lymphoblasts. Terminal deoxynucleotidyl transferase (TDT) is a template-independent DNA polymerase that plays an essential role in generating diversity for immunoglobulin genes. T-ALL/LBL patients with TDT^- have a worse prognosis. However, how TDT^- promotes the disease progression of T-ALL/LBL remains unknown. Here we analyzed the prognosis of T-ALL/LBL patients in Shanghai Children's Medical Center (SCMC) and confirmed that TDT^- patients had a higher rate of recurrence and remission failure and worse outcomes. Cellular experiments demonstrated that TDT was involved in DNA damage repair. TDT knockout delayed DNA repair, arrested the cell cycle and decreased apoptosis to induce the accumulation of chromosomal abnormalities and tolerance to abnormal karyotypes. Our study demonstrated that the poor outcomes in TDT^- T-ALL/LBL might be due to the drug resistance (VP16 and MTX) induced by chromosomal abnormalities. Our findings revealed novel functions and mechanisms of TDT in T-ALL/LBL and supported that hematopoietic stem cell transplantation (HSCT) might be a better choice for these patients.

Structural characteristics of a low molecular weight velvet antler protein and the anti-tumor activity on S180 tumor-bearing mice

Velvet antler is a traditional Chinese medicine with various pharmacological values, which is an important raw material for traditional Chinese medicinal wine. Nevertheless, the chemical compositions and bioactivities of velvet antler residue used for making medicinal wine are rarely reported, leading to a waste of resources. In this study, a velvet antler protein (VA-pro) was extracted from velvet antler residue by simulating the gastrointestinal digestion, and its composition, structural characteristics and in vivo anti-tumor activities were determined and investigated. VA-pro possessed high purity with a relatively low molecular weight as 22.589 kDa under HPLC, one- and two-dimensional electrophoresis, and it contained high contents of Pro, Gly, Glu and Ala. Besides, the secondary structure of VA-pro was dominated by β-turn and β-sheet, and VA-pro possessed similar protein sequence, isoelectric point and amino acid compositions to hypothetical protein G4228_020061. The in vivo results substantiated that VA-pro could improve the body weights and immune organ indices, increase the expressions of sera cytokines and regulate the distributions of T and B lymphocytes subsets in peripheral blood of S180 tumor-bearing mice. Furthermore, VA-pro could effectively inhibit solid S180 tumors growth by inducing S phase cell cycle arrest mediated through mitochondria. To summarize, our study provided theoretical support that VA-pro had the potential to be used as an immunopotentiator in immunocompromised or cancer-bearing hosts.

TOP1 modulation during melanoma progression and in adaptative resistance to BRAF and MEK inhibitors

In melanomas, therapy resistance can arise due to a combination of genetic, epigenetic and phenotypic mechanisms. Due to its crucial role in DNA supercoil relaxation, TOP1 is often considered an essential chemotherapeutic target in cancer. However, how TOP1 expression and activity might differ in therapy sensitive versus resistant cell types is unknown. Here we show that TOP1 expression is increased in metastatic melanoma and correlates with an invasive gene expression signature. More specifically, TOP1 expression is highest in cells with the lowest expression of MITF, a key regulator of melanoma biology. Notably, TOP1 and DNA Single-Strand Break Repair genes are downregulated in BRAFi- and BRAFi/MEKi-resistant cells and TOP1 inhibition decreases invasion markers only in BRAFi/MEKi-resistant cells. Thus, we show three different phenotypes related to TOP1 levels: i) non-malignant cells with low TOP1 levels; ii) metastatic cells with high TOP1 levels and high invasiveness; and iii) BRAFi- and BRAFi/MEKi-resistant cells with low TOP1 levels and high invasiveness. Together, these results highlight the potential role of TOP1 in melanoma progression and resistance.

A novel evaluation method for Ki-67 immunostaining in paraffin-embedded tissues

The Ki-67 labeling index is traditionally used to investigate tumor aggressiveness. However, no diagnostic or prognostic value has been associated to the heterogeneous pattern of nuclear positivity. The aims of this study were to develop a classification for the patterns of Ki-67-positive nuclei; to search scientific evidence for the Ki-67 expression and location throughout the cell cycle; and to develop a protocol to apply the classification of patterns of Ki-67-positive nuclei in squamous epithelium with different proliferative activities. Based on empirical observation of paraffin sections submitted to immunohistochemistry for the determination of Ki-67 labeling index and literature review about Ki-67 expression, we created a classification of the patterns of nuclear positivity (NP1, NP2, NP3, NP4, and mitosis). A semi-automatic protocol was developed to identify and quantify the Ki-67 immunostaining patterns in target tissues. Two observers evaluated 7000 nuclei twice to test the intraobserver reliability, and six evaluated 1000 nuclei to the interobserver evaluation. The results showed that the immunohistochemical patterns of Ki-67 are similar in the tumoral and non-tumoral epithelium and were classified without difficulty. There was a high intraobserver reliability (Spearman correlation coefficient > 0.9) and moderate interobserver agreement (k = 0.523). Statistical analysis showed that non-malignant epithelial specimens presented a higher number of NP1 (geographic tongue = 83.8 ± 21.8; no lesion = 107.6 ± 52.7; and mild dysplasia = 86.6 ± 25.8) when compared to carcinoma in Situ (46.8 ± 34.8) and invasive carcinoma (72.6 ± 37.9). The statistical evaluation showed significant difference (p < 0.05). Thus, we propose a new way to evaluate Ki-67, where the pattern of its expression may be associated with the dynamics of the cell cycle. Future proof of this association will validate the use of the classification for its possible impact on cancer prognosis and guidance on personalized therapy.