The histone code reader PHD finger protein 7 controls sex-linked disparities in gene expression and malignancy in Drosophila

Sex-dimorphic tumor growth is regulated by tumor microenvironmental and systemic signals

Tumor growth and progression involve coordinated regulation by internal, microenvironmental, and systemic signals and often display conspicuous sexual dimorphism. The mechanisms governing the integration and coordination of these signals, along with their sex-based differences, remain largely unknown. Using a Drosophila tumor model originating from nonreproductive tissue, we show that female-biased tumor growth involves multifaceted communications among tumor cells, hemocytes, and neuroendocrine insulin-producing cells (IPCs). Notch-active tumor cells recruit hemocytes carrying the tumor necrosis factor-α (TNF-α) homolog Eiger to the tumor microenvironment (TME), activating the c-Jun N-terminal kinase (JNK) pathway in tumor cells, instigating the sexually dimorphic up-regulation of cytokine Unpaired 2 (Upd2). Upd2, in turn, exerts a distal influence by modulating the release of a Drosophila insulin-like peptide (Dilp2) from IPCs. Dilp2 then activates the insulin signaling in the tumor, thereby fostering sexual-dimorphic tumor growth. Together, these findings reveal a relay mechanism involving the TME and systemic signals that collectively control the sexual dimorphism of tumor growth.

TrxT and dhd are dispensable for Drosophila brain development but essential for l(3)mbt brain tumour growth

Expression of the Drosophila cancer-germline (CG), X-linked, head-to-head gene pair TrxT and dhd is normally germline-specific but becomes upregulated in brain tumours caused by mutation in l(3)mbt. Here, we show that TrxT and dhd play a major synergistic role in the emergence of l(3)mbt tumour-linked transcriptomic signatures and tumour development, which is remarkable, taking into account that these two genes are never expressed together under normal conditions. We also show that TrxT, but not dhd, is crucial for the growth of l(3)mbt allografts, hence suggesting that the initial stages of tumour development and long-term tumour growth may depend on different molecular pathways. In humans, head-to-head inverted gene pairs are abundant among CG genes that map to the X chromosome. Our results identify a first example of an X-linked, head-to-head CG gene pair in Drosophila, underpinning the potential of such CG genes, dispensable for normal development and homoeostasis of somatic tissue, as targets to curtail malignant growth with minimal impact on overall health.

The nomograms for predicting overall and cancer-specific survival in elderly patients with early-stage lung cancer: A population-based study using SEER database

Purpose

Lung cancer is the leading cause of death from cancer and the number of operable elderly lung cancer patients is increasing, with advanced age being associated with a poorer prognosis. However, there is no easy and comprehensive prognostic assessment method for these patients.

Methods

Clinicopathological data of patients aged 65 years or older with TNM stage I-II lung cancer from 2004 to 2018 were downloaded from the SEER database. Patients from 2004 to 2015 were randomized into a training group (n = 16,457) and a validation group (n = 7,048). Data from 2016 to 2018 (n = 6,231) were used for external validation. Two nomogram prognostic models were created after independent prognostic factors connected to both overall survival (OS) and cancer-specific survival (CSS) in the training set by using univariate and multivariate Cox proportional hazards regression analysis. In turn, overall survival (OS) and cancer-specific survival (CSS) were predicted for patients at 1, 3, and 5 years. Based on the concordance index (C-index), calibration curves, area under the receiver operating characteristics (ROC) curve (AUC), the time-dependent area under the ROC curve, the validity, accuracy, discrimination, predictive ability, and clinical utility of the models were evaluated. Decision curve analysis (DCA) was used to assess the clinical value of the models.

Results

A total of 29,736 patients were included. Univariate and multivariate analyses suggested that age, race, gender, marriage, disease grade, AJCC stage, T-stage, surgery, radiotherapy, chemotherapy, and tumor size were independent risk factors for patient prognosis. These 11 variables were included in nomogram to predict OS and CSS of patients. C-indexes of OS for the training, validation and external validation sets were 0.730 (95% CI, 0.709-0.751), 0.734 (95% CI, 0.722-0.746), and 0.750 (95% CI, 0.734-0.766), respectively. The AUC results for the training and validation sets indicated good accuracy for this nomogram. The calibration curves demonstrated a high degree of concordance between actual and anticipated values, and the DCA demonstrated that the nomograms had better clinical application than the traditional TNM staging approach.

Conclusion

This study identified risk factors for survival in operable elderly lung cancer patients and established a new column line graph for predicting OS and CSS in these patients. The model has good clinical application and can be a good clinical decision-making tool for physicians and patients.

Oxidative Stress Is Associated with Overgrowth in Drosophila l(3)mbt Mutant Imaginal Discs

The loss-of-function conditions for an l(3)malignant brain tumour (l(3)mbt) in larvae reared at 29 °C results in malignant brain tumours and hyperplastic imaginal discs. Unlike the former that have been extensively characterised, little is known about the latter. Here we report the results of a study of the hyperplastic l(3)mbt mutant wing imaginal discs. We identify the l(3)mbt wing disc tumour transcriptome and find it to include genes involved in reactive oxygen species (ROS) metabolism. Furthermore, we show the presence of oxidative stress in l(3)mbt hyperplastic discs, even in apoptosis-blocked conditions, but not in l(3)mbt brain tumours. We also find that chemically blocking oxidative stress in l(3)mbt wing discs reduces the incidence of wing disc overgrowths. Our results reveal the involvement of oxidative stress in l(3)mbt wing discs hyperplastic growth.

Germline masculinization by Phf7 in D. melanogaster requires its evolutionarily novel C-terminus and the HP1-family protein HP1D3csd

Germ cells in Drosophila melanogaster need intrinsic factors along with somatic signals to activate proper sexual programs. A key factor for male germline sex determination is PHD finger protein 7 (Phf7), a histone reader expressed in the male germline that can trigger sex reversal in female germ cells and is also important for efficient spermatogenesis. Here we find that the evolutionarily novel C-terminus in Phf7 is necessary to turn on the complete male program in the early germline of D. melanogaster, suggesting that this domain may have been uniquely acquired to regulate sexual differentiation. We further looked for genes regulated by Phf7 related to sex determination in the embryonic germline by transcriptome profiling of FACS-purified embryonic gonads. One of the genes positively-regulated by Phf7 in the embryonic germline was an HP1family member, Heterochromatin Protein 1D3 chromoshadow domain (HP1D3csd). We find that this gene is needed for Phf7 to induce male-like development in the female germline, indicating that HP1D3csd is an important factor acting downstream of Phf7 to regulate germline masculinization.

lncRNA UCA1 Predicts a Poor Prognosis and Regulates Cell Proliferation and Migration by Repressing p21 and SPRY1 Expression in GC

Dysregulated expression of long non-coding RNAs (lncRNAs) has been reported in many types of cancers, indicating that it has important regulatory roles in human cancer biology. Recently, lncRNA urothelial cancer-associated 1 (UCA1) was shown to be dysregulated in many cancer types, but the detailed mechanisms remain largely unknown. In our study, we found that upregulated UCA1 is associated with poor prognosis in gastric cancer patients. Further experiments revealed that UCA1 knockdown significantly repressed the proliferation and migration both in vitro and in vivo. Moreover, RNA sequencing (RNA-seq) analysis revealed that UCA1 knockdown preferentially affected genes that are linked to cell proliferation, cell cycle, and cell migration. Mechanistically, UCA1 promotes cell proliferation progression through repressing p21 and Sprouty RTK signaling antagonist 1 (SPRY1) expression by binding to EZH2. We found that UCA1 could mediate the trimethylation of H3K27 in promoters of p21 and SPRY1. To our knowledge, this is the first report showing the global gene profile of downstream targets of UCA1 in the progression of gastric cancer. Collectively, our data reveal the important roles of UCA1 in gastric cancer (GC) oncogenesis.