SWI/SNF complex gene variations are associated with a higher tumor mutational burden and a better response to immune checkpoint inhibitor treatment: a pan-cancer analysis of next-generation sequencing data corresponding to 4591 cases

Background

Genes related to the SWItch/sucrose nonfermentable (SWI/SNF) chromatin remodeling complex are frequently mutated across cancers. SWI/SNF-mutant tumors are vulnerable to synthetic lethal inhibitors. However, the landscape of SWI/SNF mutations and their associations with tumor mutational burden (TMB), microsatellite instability (MSI) status, and response to immune checkpoint inhibitors (ICIs) have not been elucidated in large real-world Chinese patient cohorts.

Methods

The mutational rates and variation types of six SWI/SNF complex genes (ARID1A, ARID1B, ARID2, SMARCA4, SMARCB1, and PBRM1) were analyzed retrospectively by integrating next-generation sequencing data of 4591 cases covering 18 cancer types. Thereafter, characteristics of SWI/SNF mutations were depicted and the TMB and MSI status and therapeutic effects of ICIs in the SWI/SNF-mutant and SWI/SNF-non-mutant groups were compared.

Results

SWI/SNF mutations were observed in 21.8% of tumors. Endometrial (54.1%), gallbladder and biliary tract (43.4%), and gastric (33.9%) cancers exhibited remarkably higher SWI/SNF mutational rates than other malignancies. Further, ARID1A was the most frequently mutated SWI/SNF gene, and ARID1A D1850fs was identified as relatively crucial. The TMB value, TMB-high (TMB-H), and MSI-high (MSI-H) proportions corresponding to SWI/SNF-mutant cancers were significantly higher than those corresponding to SWI/SNF-non-mutant cancers (25.8 vs. 5.6 mutations/Mb, 44.3% vs. 10.3%, and 16.0% vs. 0.9%, respectively; all p  < 0.0001). Furthermore, these indices were even higher for tumors with co-mutations of SWI/SNF genes and MLL2/3. Regarding immunotherapeutic effects, patients with SWI/SNF variations showed significantly longer progression-free survival (PFS) rates than their SWI/SNF-non-mutant counterparts (hazard ratio [HR], 0.56 [95% confidence interval {CI} 0.44–0.72]; p < 0.0001), and PBRM1 mutations were associated with relatively better ICI treatment outcomes than the other SWI/SNF gene mutations (HR, 0.21 [95% CI 0.12–0.37]; p = 0.0007). Additionally, patients in the SWI/SNF-mutant + TMB-H (HR, 0.48 [95% CI 0.37–0.54]; p  < 0.0001) cohorts had longer PFS rates than those in the SWI/SNF-non-mutant + TMB-low cohort.

Conclusions

SWI/SNF complex genes are frequently mutated and are closely associated with TMB-H status, MSI-H status, and superior ICI treatment response in several cancers, such as colorectal cancer, gastric cancer, and non-small cell lung cancer. These findings emphasize the necessity and importance of molecular-level detection and interpretation of SWI/SNF complex mutations.

[Clinical observation of microsurgical removal of the hemilateral tuberculum sellae meningiomas through contralateral eyebrow arch approach]

The current study aimed to investigate the clinical feasibility of microscopic resection of hemilateral tuberculum sellae meningiomas (TSM) via the contralateral eye brow arch approach. The clinical data of 34 patients with TSM who underwent microsurgery from January 2016 to June 2021 in the Neurosurgery Department of Ruijin Hospital Affiliated to Shanghai Jiaotong University School of Medicine and the First Affiliated Hospital of Henan University were collected and reviewed. The postoperative visual acuity improvement rate was 88.5% (23/26), and the total tumor resection rate was 88.2% (30/34); the postoperative visual acuity improvement in patients with total tumor resection was better than that of patients with partial resection [90.9% (20/22) vs 3/4]. Meanwhile, the postoperative visual acuity improvement in patients with the superior optic nerve and laterl-superior optic nerve was better than that of patients with the lateral optic nerve type (12/14, 8/8 vs 3/4). Supraorbital skin numbness occurred in 3 cases after operation, and the symptoms disappeared during follow-up; 2 cases had mild disturbance of hormone level, and urine output of 2 cases increased after operation, which returned to normal level after symptomatic treatment; 1 case had subcutaneous effusion which was absorbed after treatment. There were no complications such as olfactory disturbance and intracranial infection. During follow-up for 3-60 (33±6) months, recurrence occurred in 2 cases and reoperation was performed. For the hemilateral TSM, according to the preoperative evaluation of the origin of the TSM and the side with visual impairment, the contralateral eyebrow approach is selected to fully expose the tumor base below the optic nerve. It is beneficial to fully resect the tumor under direct vision, and the symptoms of postoperative visual impairment are significantly improved, indicating that the current surgical method can be used in the clinical setting.

[VIPR1 promoter methylation promotes transcription factor AP-2α binding to inhibit VIPR1 expression and promote hepatocellular carcinoma cell growth in vitro]

OBJECTIVE

To explore the transcriptional regulation mechanism and biological function of low expression of vasoactive intestinal peptide receptor 1 (VIPR1) in hepatocellular carcinoma (HCC).

METHODS

We constructed plasmids carrying wild-type VIPR1 promoter or two mutant VIPR1 promoter sequences for transfection of the HCC cell lines Hep3B and Huh7, and examined the effect of AP-2α expression on VIPR1 promoter activity using dual-luciferase reporter assay. Pyrosequencing was performed to detect the changes in VIPR1 promoter methylation level in HCC cells treated with a DNA methyltransferase inhibitor (DAC). Chromatin immunoprecipitation was used to evaluate the binding ability of AP-2α to VIPR1 promoter. Western blotting was used to assess the effect of AP-2α knockdown on VIPR1 expression and examine the differential expression of VIPR1 in the two cell lines. The effects of VIPR1 overexpression and knockdown on the proliferation, cell cycle and apoptosis of HCC cells were analyzed using CCK8 assay and flow cytometry. We also observed the growth of HCC xenograft with lentivirus-mediated over-expression of VIPR1 in nude mice.

RESULTS

Compared with the wild-type VIPR1 promoter group, co-transfection with the vector carrying two promoter mutations and the AP-2α-over-expressing plasmid obviously restored the luciferase activity in HCC cells (P < 0.05). DAC treatment of the cells significantly decreased the methylation level of VIPR1 promoter and inhibited the binding of AP-2α to VIPR1 promoter (P < 0.01). The HCC cells with AP-2α knockdown showed increased VIPR1 expression, which was lower in Huh7 cells than in Hep3B cells. VIPR1 overexpression in HCC cells caused significant cell cycle arrest in G2/M phase (P < 0.01), promoted cell apoptosis (P < 0.001), and inhibited cell proliferation (P < 0.001), while VIPR1 knockdown produced the opposite effects. In the tumor-bearing nude mice, VIPR1 overexpression in the HCC cells significantly suppressed the increase of tumor volume (P < 0.001) and weight (P < 0.05).

CONCLUSION

VIPR1 promoter methylation in HCC promotes the binding of AP-2α and inhibits VIPR1 expression, while VIPR1 overexpression causes cell cycle arrest, promotes cell apoptosis, and inhibits cell proliferation and tumor growth.

Genome sequence and population genomics provide insights into chromosomal evolution and phytochemical innovation of Hippophae rhamnoides

Plants of the Elaeagnaceae family are widely used to treat various health disorders owing to their natural phytochemicals. Seabuckthorn (Hippophae rhamnoides L.) is an economically and ecologically important species within the family with richness of biologically and pharmacologically active substances. Here, we present a chromosome-level genome assembly of seabuckthorn (http://hipp.shengxin.ren/), the first genome sequence of Elaeagnaceae, which has a total length of 849.04 Mb with scaffold N50 of 69.52 Mb and 30 864 annotated genes. Two sequential tetraploidizations with one occurring ~36-41 million years ago (Mya) and the last ~24-27 Mya were inferred, resulting in expansion of genes related to ascorbate and aldarate metabolism, lipid biosynthesis, and fatty acid elongation. Comparative genomic analysis reconstructed the evolutionary trajectories of the seabuckthorn genome with the predicted ancestral genome of 14 proto-chromosomes. Comparative transcriptomic and metabonomic analyses identified some key genes contributing to high content of polyunsaturated fatty acids and ascorbic acid (AsA). Additionally, we generated and analysed 55 whole-genome sequences of diverse accessions, and identified 9.80 million genetic variants in the seabuckthorn germplasms. Intriguingly, genes in selective sweep regions identified through population genomic analysis appeared to contribute to the richness of AsA and fatty acid in seabuckthorn fruits, among which GalLDH, GMPase and ACC, TER were the potentially major-effect causative genes controlling AsA and fatty acid content of the fruit, respectively. Our research offers novel insights into the molecular basis underlying phytochemical innovation of seabuckthorn, and provides valuable resources for exploring the evolution of the Elaeagnaceae family and molecular breeding.

O-057 The pregnant outcome after laparoscopy treatment for subtle distal fallopian tube abnormalities in infertile population: a prospective cohort study

Study question

What is the the pregnancy outcome after laparoscopy treatment for subtle distal fallopian tube abnormalities and the factors related with natural pregnancy.

Summary answer

The natural pregnancy rate is 46.58% after laparoscopy and patients' age, duration time of infertility and concurrent number of abnormalities are related with natural pregnancy.

What is known already

Subtle distal fallopian tube abnormalities are a group of diseases that are characterized by subtle variations in tubal anatomy including fimbrial agglutination, tubal diverticula, accessory ostium, fimbrial phimosis, and accessory fallopian tube. The prevalence of subtle distal fallopian tube abnormalities is high in infertile women.This group of diseases is highly related to endometriosis, especially its early stage, and may indicate fimbrial abnormalities in endometriosis.

Study design, size, duration

This was a prospective cohort study conducted in the Reproductive Medicine Center of an university-affiliated teaching hospital from January 2017 to December 2018.

Participants/materials, setting, methods

234 patients with subtle distal fallopian tube abnormalities were included. Laparoscopies were performed by four senior reproductive surgeons who were familiar with the diagnostic criteria and surgery treatment for subtle abnormalities. The fallopian tube abnormalities were corrected and endometriosis was treated by either electrical ablation for peritoneal lesions or endometrioma excision.The participants were followed up by phone every 12 months for pregnancy outcome until 36 months after surgery.

Main results and the role of chance

167 patients conceived after surgery(clinical pregnancy rate 71.37%). 109 patients conceived naturally (natural pregnancy rate 46.58%) and 59 patients conceived after in IVF（One case conceived naturally after live birth after IVF, four cases conceived naturally twice) . The average time for natural conception after surgery is 8.36±7.47 months. 51.4% of natural pregnancy occurred within 6 months and 79.8% occurred within 12 months.Among the 109 naturally conceived patients, there were 94 cases of live birth, 13 cases of natural abortion (natural abortion rate 11.92%) and 2 cases of ectopic pregnancy (ectopic pregnancy rate 1.83%). No preterm birth, multiple pregnancy or birth defects were reported in this group.The patient age(HR = 0.917,95%CI 0.870-0.917,P=0.001), duration of infertility(HR = 0.846,95%CI 0.740-0.966,P=0.014) and concurrent number of subtle abnormalities (HR = 0.636,95%CI 0.416-0.970,P=0.036) are the factors associated with natural pregnancy. The type of subtle abnormalities, type of infertility, body mess index, concurrent endometriosis, uterine cavity abnormalities and myoma are not related with natural pregnancy.

Limitations, reasons for caution

Not all kinds of subtle distal abnormalities are included such as paratubal cyst is excluded from the study. Not all the patients had the test of ovarian reserve such as AMH, antral follicle count and FSH level, so we couldn’t evaluate the relationship between ovarian reserve and natural pregnancy.

Wider implications of the findings

This is the largest clinical study that investigated the pregnancy outcome of subtle fallopian tube abnormalities in the infertile population.Laparoscopy surgery is an effective treatment for infertility patients with subtle distal fallopian tube abnormalities, especially for the young, short duration time of infertility and ≤2 types of subtle abnormalities.

Trial registration number

ChiCTR2000029095

P-752 Fertility outcomes after hysteroscopic niche resection compared with expectant management in patients with a niche in the uterine cesarean scar

Study question

Whether hysteroscopic niche resection is suitable for patients with a niche in the uterine cesarean scar and with fertility desire compared with expectant management.

Summary answer

Hysteroscopic niche resection is a effective treatment for patients with fertility desire compared with expectant management and satisfactory obstetrical outcomes could be achieved.

What is known already

The specific treatment method for niche should be determined according to the patient’s symptoms, fertility desire and niche features,up to now, hysteroscopic niche resection has been shown effective to reduce abnormal uterine bleeding. However, similar to expectant treatment, hysteroscopic niche resection does not reconstruct the lower uterine segment, whether hysteroscopic niche resection affect fertility outcomes remains controversial.

Study design, size, duration

We designed a single-center retrospective cohort study. We included patients with desire to conceive that underwent hysteroscopic niche resection or expectant management between 2016.9-2020.12. The date of entry for each woman was the date of treatment or the date that the niche was diagnosed. The last day of analysis was the date of the first delivery or the last follow-up visit in women who remained non-livebirth.

Participants/materials, setting, methods

This study was conducted in a university-affiliated gynecology hospital. A total of 71 patients that underwent hysteroscopic niche resection and 97 patients that underwent expectant management were recruited. All women were followed up yearly until December 2021 for the occurrence of live birth. A Cox proportional hazards regression model with potential variables to identify predictors of pregnancy was also processed.

Main results and the role of chance

Baseline characteristics of age, gravidity, parity, previous cesarean section, and anatomical indicators of niche were not significantly different between the groups. However patients in the hysteroscopic niche resection had a longer menstruation duration (hysteroscopic niche resection vs expectant management as 12(10/14) vs 7(7/10), P &lt;0.001) and a longer infertility period before treatment(hysteroscopic niche resection vs expectant management as 48.00±36.28 vs 23.11±20.34, P = 0.014). The overall live birth rate was similar in both groups (hysteroscopic niche resection vs expectant management as 37/71 [52.11%] vs 40/97 [41.23%], P = 0.162). For the live births in the two groups, no uterine rupture occurred.The total pregnancy rate was higher in the hysteroscopic niche resection group (hysteroscopic niche resection vs expectant management as 50/71 [70.40%] vs 50/97 [51.54%], P = 0.014). What’s more, for patients with infertility before treatment,there was a statistically significant difference regarding time to pregnancy between the two groups (P = 0.049).

After adjustment for confounding factors including age, numbers of cesarean section, infertility peroid before treatment, anatomical indicators of niche and menstruation duration, cox proportional hazards analysis revealed that women underwent hysteroscopic niche resection were positively correlated to pregnancy (AHR = 1.646, 95% CI [1.081-2.506]).

Limitations, reasons for caution

This study was a single-center retrospective cohort study, to strengthen the conclusion, more prospective studies that include larger sample sizes and multiple centers should be conducted.

Wider implications of the findings

For asymptomatic cesarean scar defect patients whose residual myometrium thickness is sufficient, the expectant treatment is practical. However, for patients with abnormal uterine bleeding or infertility, hysteroscopic niche resection should be recommended.

Trial registration number

not applicable

P-744 Fertility intention for a second or third child among childbearing couple in Shanghai, China

Study question

What is the intention rate and related factors for a second or third child among childbearing couple?

Summary answer

Among couples with one child, 16.2% are willing to have a second child. Only 9.4% of couples with two children are pursuing third child.

What is known already

The decline in fertility is becoming an inevitable trend in most countries around the world. In the end of 1970s, the one-child policy was implemented. Since 21st century, China has gradually changed its fertility policy, from a selective two-child policy to a comprehensive two-child policy. Nevertheless, the number of total annual births in China has not shown an obviously increasing trend of growth. On August 20, 2021, the Chinese government amended the law to allow a couple to have three children. However, only a few studies have been conducted to evaluate fertility intention in the couples who already have kids.

Study design, size, duration

We conducted a cross-sectional survey in Shanghai from July to August in 2021. This study population was based on the female fertility database established between 2013 and 2017, which contains basic sociodemographic information and the reproductive intentions. We conducted this study to evaluate the fertility intention of the second or the third child and its related factors.

Participants/materials, setting, methods

From July to August in 2021, couples aged between 20 and 45 years old with one or two children was invited to participate in our study to give the information about “second/third births intention” and the factors that may probably related to it. Between the groups with and without second/third child intention, the chi-squared test and binary logistic regression was applied to compare the difference in the basic characteristics and relative factors.

Main results and the role of chance

Among couples with one child, 130 (16.2%) couples had intention to have a second child. Only 9.4% of couples with two children show the desire to have a third child. The ideal number of children for all our participants was 1.72±0.52. And the ideal number of children among couples with one child is 1.61±0.52. By contrast, the ideal number for couples with two kids was 2.06±0.34. The study showed great differences in Socioeconomic and personal factors between two groups. For second-child intention, the female age over 35 years, first child's age over 7 years, annual payment for the first child ranges from 70,000-100,000 RMB and children’s educational barriers were negatively associated with an intention to have a second child. Job with more free time makes it easier for couples to have a second child. Among couples with two children, parents with family financial constraints and children’s educational barriers are less likely to have a third child. Fertility-encouraged government policy can promote couples to pursue a second or third child. It is necessary to take measures to reduce the burden of raising children and increase free time for couples to relief parent’s pressure of rearing a child.

Limitations, reasons for caution

As this is a single-center study in Shanghai, the sample size is relatively small. Although our sample size still meets the basic statistical requirements and can detect a moderate effect size as significance, the results may not be applicable to some other regions.

Wider implications of the findings

The decision of fertility intention is influenced by female age, the first child’s age, family economic conditions, children’s education and national fertility policies. It is necessary to take measures to reduce the burden of raising children and increase free time for couples to relief parent’s pressure of rearing a child.

Trial registration number

ChiCTR2100045315

Genome-wide DNA N6-adenine methylation in sea buckthorn (Hippophae rhamnoides L.) fruit development

As a new epigenetic mark, DNA N6-adenine (6mA) methylation plays an important role in various biological processes and has been reported in many prokaryotic organisms in recent years. However, the distribution patterns and functions of DNA 6mA modification have been poorly studied in non-model crops. In this study, we observed that the methylation ratio of 6mA was about 0.016% in the sea buckthorn (Hippophae rhamnoides L.) genome using mass spectrometry. We first constructed a comprehensive 6mA landscape in sea buckthorn genome using nanopore sequencing at single-base resolution. Distribution analysis suggested that 6mA methylated sites were widely distributed in the sea buckthorn chromosomes, which were similar to those in Arabidopsis and rice. Furthermore, reduced 6mA DNA methylation is associated with different expression of genes related to the fruit-ripening process in sea buckthorn. Our results revealed that 6mA DNA modification could be considered an important epigenomic mark and contributes to the fruit ripening process in plants.

Transcriptome and DNA methylome provide insights into the molecular regulation of drought stress in sea buckthorn

Sea buckthorn is a typical drought-resistant tree species. However, there is a general lack of understanding of the pattern of DNA methylation linked with sea buckthorn responses to drought, and its relationship with drought tolerance mechanisms. In this study, we performed whole-transcriptome RNA sequencing and methylome sequencing in response to drought stress to explore differentially expressed mRNAs, miRNAs, lncRNAs and circRNAs in sea buckthorn leaves. Based on predicted DE pairs, we constructed a competitive endogenous RNA network, which revealed potential transcriptional regulatory roles in response to drought stress. The results of methylome sequencing revealed that the DNA methylation level was increased in sea buckthorn leaves under drought stress. We identified 13,405 differentially methylated regions between CK and TR. We found one DMR-associated DEG (Vacuolar-sorting receptor 6) involved in the ABA accumulation pathway. In addition, two DNA methyltransferases (HrMET1 and HrDRM1) were closely associated with drought-induced hypermethylation in sea buckthorn. Together, we firstly conducted a comprehensive transcriptomic and epigenetic analysis of sea buckthorn under drought stress, providing a resource for further study of the potential functions of genes, miRNAs, lncRNAs, circRNAs and DNA methyltransferases.

[Primary ovarian squamous cell carcinoma: clinicopathological features and prognostic analysis of fifteen cases]

Objective: To assess the clinical features and treatment outcomes in patients with primary ovarian squamous cell carcinoma (POSCC). Methods: Fifteen patients with primary ovarian squamous cell carcinoma diagnosed from January 2009 to December 2018 in Cancer Hospital of the University of Chinese Academy of Sciences were collected. The expression of p16, hMLH1, hMSH2, hMSH6 and PMS2 in POSCC was detected by immunohistochemistry, and the status of high-risk human papillomavirus (HPV) by RNAscope test. Results: Squamous cell carcinoma with different degrees of differentiation was found in 15 cases, including three cases with high differentiation and 12 cases with medium to low differentiation. There were four cases with in situ squamous cell carcinoma, four cases with teratoma, one case with endometrial carcinoma/atypical hyperplasia, and one case with endometriosis. p16 was expressed in five cases (5/15), indicating coexisting high-risk HPV infection. There was no high-risk HPV infection in the remaining 10 cases, and p16 staining was negative. There was no deficient mismatch repair protein in all cases. The overall survival time (P=0.038) and progression free survival (P=0.045) of patients with high-risk HPV infection were longer than those without HPV infection. Conclusions: POSCC is more commonly noted in postmenopausal women and often occurs unilaterally. Elevated serological indexes CA125 and SCC are the most common finding. Morphologically, the tumors show variable degrees of differentiation, but the current data suggest that the degree of differentiation cannot be used as an independent prognostic index. High-risk HPV infection may be associated with the occurrence of POSCC, and that the prognosis of POSCC patients with HPV infection is better than that of patients without infection.

Unique features of the m6A methylome and its response to drought stress in sea buckthorn (Hippophae rhamnoides Linn.)

In plants, recent studies have revealed that N6-methyladenosine (m⁶A) methylation of mRNA has potential regulatory functions of this mRNA modification in many biological processes. m⁶A methyltransferase, m⁶A demethylase and m⁶A-binding proteins can cause differential phenotypes, indicating that m⁶A may have critical roles in the plant. In this study, we depicted the m⁶A map of sea buckthorn (Hippophae rhamnoides Linn.) transcriptome. Similar to A. thaliana, m⁶A sites of sea buckthorn transcriptome is significantly enriched around the stop codon and within 3'-untranslated regions (3'UTR). Gene ontology analysis shows that the m⁶A modification genes are associated with metabolic biosynthesis. In addition, we identified 13,287 different m⁶A peaks (DMPs) between leaf under drought (TR) and control (CK) treatment. It reveals that m⁶A has a high level of conservation and has a positive correlation with mRNA abundance in plants. GO and KEGG enrichment results showed that DMP modification DEGs in TR were particularly associated with ABA biosynthesis. Interestingly, our results showed three m⁶A demethylase (HrALKBH10B, HrALKBH10C and HrALKBH10D) genes were significantly increased following drought stress, which indicated that it may contributed the decreased m⁶A levels. This exhaustive m⁶A map provides a basis and resource for the further functional study of mRNA m⁶A modification in abiotic stress.

Spatial modulation of individual behaviors enables an ordered structure of diverse phenotypes during bacterial group migration

Coordination of diverse individuals often requires sophisticated communications and high-order computational abilities. Microbial populations can exhibit diverse individualistic behaviors, and yet can engage in collective migratory patterns with a spatially sorted arrangement of phenotypes. However, it is unclear how such spatially sorted patterns emerge from diverse individuals without complex computational abilities. Here, by investigating the single-cell trajectories during group migration, we discovered that, despite the constant migrating speed of a group, the drift velocities of individual bacteria decrease from the back to the front. With a Langevin-type modeling framework, we showed that this decreasing profile of drift velocities implies the spatial modulation of individual run-and-tumble random motions, and enables the bacterial population to migrate as a pushed wave front. Theoretical analysis and stochastic simulations further predicted that the pushed wave front can help a diverse population to stay in a tight group, while diverse individuals perform the same type of mean reverting processes around centers orderly aligned by their chemotactic abilities. This mechanism about the emergence of orderly collective migration from diverse individuals is experimentally demonstrated by titration of bacterial chemoreceptor abundance. These results reveal a simple computational principle for emergent ordered behaviors from heterogeneous individuals.

Organisms living in large groups often have to move together in order to navigate, forage for food, and increase their roaming range. Such groups are often made up of distinct individuals that must integrate their different behaviors in order to migrate in the same direction at a similar pace. For instance, for the bacteria Escherichia coli to travel as a condensed group, they must coordinate their response to a set of chemical signals called chemoattractants that tell them where to go.

The chemoattractants surrounding the bacteria are unequally distributed so that there is more of them at the front than the back of the group. During migration, each bacterium moves towards this concentration gradient in a distinct way, spontaneously rotating its direction in a ‘run-and-tumble’ motion that guides it towards areas where there are high levels of these chemical signals. In addition to this variability, how well individual bacteria are able to swim up the gradient also differs within the population. Bacteria that are better at sensing the chemoattractant gradient are placed at the front of the group, while those that are worst are shifted towards the back. This spatial arrangement is thought to help the bacteria migrate together. But how E. coli organize themselves in to this pattern is unclear, especially as they cannot communicate directly with one another and display such diverse, randomized behaviors.

To help answer this question, Bai, He et al. discovered a general principle that describes how single bacterial cells move within a group. The results showed that E. coli alter their run-and-tumble motion depending on where they reside within the population: individuals at the rear drift faster so they can catch up with the group, while those leading the group drift slower to draw themselves back. This ‘reversion behavior’ allows the migrating bacteria to travel at a constant speed around a mean position relative to the group.

A cell’s drifting speed is determined by how well it moves towards the chemoattractant and its response to the concentration gradient. As a result, the mean position around which the bacterium accelerates or deaccelerates will vary depending on how sensitive it is to the chemoattractant gradient. The E. coli therefore spatially arrange themselves so that the more sensitive bacteria are located at the front of the group where the gradient is shallower; and cells that are less sensitive are located towards the back where the gradient is steeper.

These findings suggest a general principle for how bacteria form ordered patterns whilst migrating as a collective group. This behavior could also apply to other populations of distinct individuals, such as ants following a trail or flocks of birds migrating in between seasons.

Inherited Mutations in Chinese Men With Prostate Cancer

BACKGROUND

Although China accounts for 7.8% of worldwide new prostate cancer (PCa) cases and 14.5% of new deaths according to GLOBOCAN 2020, the risk of PCa associated with germline mutations is poorly defined, hampered in part by lack of nationwide evidence. Here, we sequenced 19 PCa predisposition genes in 1,836 Chinese patients with PCa and estimated disease risk associated with inherited mutations.

PATIENTS AND METHODS

Patients were recruited from 4 tertiary cancer centers (n=1,160) and a commercial laboratory (n=676). Germline DNA was sequenced using a multigene panel, and pathogenic/likely pathogenic (P/LP) mutation frequencies in patients with PCa were compared with populations from the gnomAD (Genome Aggregation Database) and ChinaMAP (China Metabolic Analytics Project) databases. Clinical characteristics and progression-free survival were assessed by mutation status.

RESULTS

Of 1,160 patients from hospitals, 89.7% had Gleason scores ≥8, and 65.6% had metastases. P/LP mutations were identified in 8.49% of Chinese patients with PCa. Association with PCa risk was significant for mutations in ATM (odds ratio [OR], 5.9; 95% CI, 3.1-11.1), BRCA2 (OR, 15.3; 95% CI, 10.0-23.2), MSH2 (OR, 15.8; 95% CI, 4.2-59.6), and PALB2 (OR, 5.9; 95% CI, 2.7-13.2). Compared with those without mutations, patients with mutations in ATM, BRCA2, MSH2, or PALB2 showed a poor outcome with treatment using androgen deprivation therapy and abiraterone (hazard ratio, 2.19 [95% CI, 1.34-3.58] and 2.47 [95% CI, 1.23-4.96], respectively) but similar benefit from docetaxel.

CONCLUSIONS

The present multicenter study confirmed that a significant proportion of Chinese patients with PCa had inherited mutations and identified predisposition genes in this underreported ethnicity. These data provide empirical evidence for precision prevention and prognostic estimation in Chinese patients with PCa.

Evaluation of different late left ventricular remodeling definitions for predicting long-term outcomes in acute myocardial infarction patients undergoing percutaneous coronary intervention

Background

Late left ventricular remodeling (LLVR) after the index acute myocardial infarction (AMI) is a common complication, and is associated with poor outcome. However, the optimal definition of LLVR has been debated because of its different incidence and influence on prognosis. At present, there are limited data regarding the influence of different LLVR definitions on long-term outcomes in AMI patients undergoing percutaneous coronary intervention (PCI).

Purpose

To explore the impact of different definitions of LLVR on long-term mortality, re-hospitalization or an urgent visit for heart failure, and identify which definition was more suitable for predicting long-term outcomes in AMI patients undergoing PCI.

Methods

We prospectively observed 460 consenting first-time AMI patients undergoing PCI from January 2012 to December 2018. LLVR was defined as a ≥20% increase in left ventricular end-diastolic volume (LVEDV), or a &gt;15% increase in left ventricular end-systolic volume (LVESV) from the initial presentation to the 3–12 months follow-up, or left ventricular ejection fraction (LVEF) &lt;50% at follow up. These parameters of the cardiac structure and function were measuring through the thoracic echocardiography. The association of LLVR with long-term prognosis was investigated by Cox regression analysis.

Results

The incidence rate of LLVR was 38.1% (n=171). The occurrence of LLVR according to LVESV, LVEDV and LVEF definition were 26.6% (n=117), 31.9% (n=142) and 11.5% (n=51), respectively. During a median follow-up of 2 years, after adjusting other potential risk factors, multivariable Cox regression analysis revealed LLVR of LVESV definition [hazard ratio (HR): 2.50, 95% confidence interval (CI): 1.19–5.22, P=0.015], LLVR of LVEF definition (HR: 16.46, 95% CI: 6.96–38.92, P&lt;0.001) and LLVR of Mix definition (HR: 5.86, 95% CI: 2.45–14.04, P&lt;0.001) were risk factors for long-term mortality, re-hospitalization or an urgent visit for heart failure. But only LLVR of LVEF definition was a risk predictor for long-term mortality (HR: 6.84, 95% CI: 1.98–23.65, P=0.002).

Conclusions

LLVR defined by LVESV or LVEF may be more suitable for predicting long-term mortality, re-hospitalization or an urgent visit for heart failure in AMI patients undergoing PCI. However, only LLVR defined by LVEF could be used for predicting long-term mortality.

Funding Acknowledgement

Type of funding sources: None. Association Between LLVR and outcomesKaplan-Meier Estimates of the Mortality

Predictive value of neutrophil percentage-to-albumin ratio for contrast-associated acute kidney injury in patients without chronic kidney disease undergoing elective percutaneous coronary intervention

Background

Although previous studies have demonstrated that neutrophil and albumin are biomarkers of inflammation and malnutrition, which are highly related with contrast-associated acute kidney injury (CA-AKI). However, there has been no study investigated the combined evaluation of neutrophil and albumin in predicting CA-AKI.

Purpose

To explore the predictive value of neutrophil percentage-to-albumin ratio (NPAR) for CA-AKI in patients undergoing elective percutaneous coronary intervention (PCI).

Methods

We prospectively observed 5083 consenting patients without chronic kidney disease (CKD) undergoing elective PCI from January 2012 to December 2018. NPAR was calculated as neutrophil percentage numerator divided by serum albumin concentration. CA-AKI was defined as an increase in serum creatinine (SCr) ≥50% or 0.3 mg/dL within 48 hours after contrast medium exposure. The association between NPAR and CA-AKI was investigated by logistic regression analysis. The area under the receiver-operating characteristic curve (AUC), continuous net reclassification improvement (NRI), and integrated discrimination improvement (IDI) were calculated to make comparison for CA-AKI prediction.

Result

The incidence of CA-AKI was 5.6% (n=286). The median NPAR was 14.9 (13.0–17.1). According to the receiver operating characteristic curves (ROC), the best cut-off value of NPAR for predicting CA-AKI was 15.7 with 66.8% sensitivity and 61.9% specificity (C statistic=0.679; 95% CI, 0.666–0.691). NPAR displayed higher AUC value in comparison to neutrophil percentage (p&lt;0.001), but not albumin (P=0.063), as a predictor of CA-AKI. However, NPAR significantly improved the prediction of CA-AKI in the continuous NRI and IDI over neutrophil percentage (NRI: 0.353, 95% CI: 0.234–0.472, P&lt;0.001; IDI: 0.017, 95% CI: 0.010–0.024, p&lt;0.001) and albumin (NRI: 0.141, 95% CI: 0.022–0.260, P=0.020; IDI: 0.009, 95% CI: 0.003–0.015, p=0.003) alone. After adjusting for potential confounding risk factors of CA-AKI, multivariable logistic analysis showed that NPAR &gt;15.7 was a strong independent predictor of CA-AKI (OR=1.998, 95% CI, 1.511–2.643, p&lt;0.001).

Conclusion

NPAR is an independent predictor of CA-AKI, which significantly improved the prediction of CA-AKI over neutrophil and albumin alone in patients without CKD undergoing elective PCI.

Funding Acknowledgement

Type of funding sources: None. ROC for NPAR to predict CA-AKIPredictors of CA-AKI

The De-Ritis ratio is associated with contrast-associated acute kidney injury in patients undergoing elective percutaneous coronary intervention

Background

Preoperative liver dysfunction has been demonstrated as a poor prognostic factor after major surgery. Recent researches discovered that an increased De-Ritis ratio (aspartate aminotransferase-to-alanine aminotransferase ratio) reflects the liver dysfunction and was associated with adverse cardiovascular and renal outcomes. However, there is a lack of data exploring the predictive value of the De-Ritis ratio on contrast-associated acute kidney injury (CA-AKI) in patients undergoing elective percutaneous coronary intervention (PCI).

Purpose

To evaluate the predictive value of the De-Ritis ratio for CA-AKI in patients undergoing elective PCI.

Methods

We conducted a prospective, observational study with 5780 consenting patients undergoing elective PCI from January 2012 to December 2018. CA-AKI was defined as an increase in serum creatinine (SCr) ≥50% or 0.3 mg/dL within 48 hours after contrast medium exposure. The relationship between the De-Ritis ratio and CA-AKI was investigated by logistic regression analysis. The predictive utility of the De-Ritis ratio was determined and compared using the area under the receiver-operating characteristic curve (AUC).

Result

CA-AKI developed in 363 (6.3%) patients. The median De-Ritis ratio was 1.00 (0.77–1.33). The De-Ritis ratio showed an AUC of 0.636 (95% confidence interval (CI): 0.624–0.649; P&lt;0.001) in predicting CA-AKI, which was significantly greater than aspartate aminotransferase (AST) (AUC: 0.636 vs 0.589, p=0.015) and alanine aminotransferase (ALT) (AUC: 0.636 vs 0.506, p&lt;0.001). The best cut-off value of the De-Ritis ratio for predicting CA-AKI was 1.30 with 47.1% sensitivity and 74.7% specificity. Multivariable logistic analysis showed that the De-Ritis ratio &gt;1.30 was a remarkable independent predictor of CA-AKI (OR=1.757, 95% CI, 1.385–2.229, p&lt;0.001) even after adjusting for other CA-AKI risk factors.

Conclusion

The De-Ritis ratio is an independent risk factor for predicting CA-AKI in patients undergoing elective PCI.

Funding Acknowledgement

Type of funding sources: None. ROC for De-Ritis ratio to predict CA-AKIPredictors of CA-AKI

Phase I/II study of single-agent lenvatinib in children and adolescents with refractory or relapsed solid malignancies and young adults with osteosarcoma (ITCC-050)☆

Background

We report results from the phase I dose-finding and phase II expansion part of a multicenter, open-label study of single-agent lenvatinib in pediatric and young adult patients with relapsed/refractory solid tumors, including osteosarcoma and radioiodine-refractory differentiated thyroid cancer (RR-DTC) (NCT02432274).

Patients and methods

The primary endpoint of phase I was to determine the recommended phase II dose (RP2D) of lenvatinib in children with relapsed/refractory solid malignant tumors. Phase II primary endpoints were progression-free survival rate at 4 months (PFS-4) for patients with relapsed/refractory osteosarcoma; and objective response rate/best overall response for patients with RR-DTC at the RP2D.

Results

In phase I, 23 patients (median age, 12 years) were enrolled. With lenvatinib 14 mg/m², three dose-limiting toxicities (hypertension, n = 2; increased alanine aminotransferase, n = 1) were reported, establishing 14 mg/m² as the RP2D. In phase II, 31 patients with osteosarcoma (median age, 15 years) and 1 patient with RR-DTC (age 17 years) were enrolled. For the osteosarcoma cohort, PFS-4 (binomial estimate) was 29.0% [95% confidence interval (CI) 14.2% to 48.0%; full analysis set: n = 31], PFS-4 by Kaplan–Meier estimate was 37.8% (95% CI 20.0% to 55.4%; full analysis set) and median PFS was 3.0 months (95% CI 1.8-5.4 months). The objective response rate was 6.7% (95% CI 0.8% to 22.1%). The patient with RR-DTC had a best overall response of partial response. Some 60.8% of patients in phase I and 22.6% of patients in phase II (with osteosarcoma) had treatment-related treatment-emergent adverse events of grade ≥3.

Conclusions

The lenvatinib RP2D was 14 mg/m². Single-agent lenvatinib showed activity in osteosarcoma; however, the null hypothesis could not be rejected. The safety profile was consistent with previous tyrosine kinase inhibitor studies. Lenvatinib is currently being investigated in osteosarcoma in combination with chemotherapy as part of a randomized, controlled trial (NCT04154189), in pediatric solid tumors in combination with everolimus (NCT03245151), and as a single agent in a basket study with enrollment ongoing (NCT04447755).

•

The recommended phase II dose of lenvatinib in children with relapsed/refractory solid malignant tumors is 14 mg/m².

•

This dose is equivalent to the recommended dose of 24 mg/day for single-agent lenvatinib in adults with DTC.

•

Single-agent lenvatinib showed activity of interest in children and young adults with osteosarcoma.

•

Based on this initial report, lenvatinib is currently being investigated in combination with chemotherapy in osteosarcoma.

P Doping Promotes the Spontaneous Visible-Light-Driven Photocatalytic Water Splitting in Isomorphic Type II GaSe/InS Heterostructure

The development and design of clean and efficient water splitting photocatalysts is important for the current situation of energy shortage and environmental pollution. A new type of isomorphic GaSe/InS heterostructure is constructed, and the optoelectronic properties were studied through first-principles calculations. The results show that GaSe/InS vdW heterostructure is a type II semiconductor with a band gap of 2.09 eV. However, through the analysis of the energy band edge position and Gibbs free energy change of water splitting, it is found that the GaSe/InS heterostructure is difficult to undergo overall water splitting. Therefore, nonmetallic element P doping is considered, the established P-doped GaSe/InS (P-GaSe/InS) heterostructure could maintain the type II band arrangement, and under acidic conditions, P-GaSe/InS heterostructure could spontaneously undergo overall water splitting thermodynamically. Furthermore, the low exciton binding energy of P-GaSe/InS heterostructure highlights better light absorption performance. Therefore, these findings indicate that P-GaSe/InS heterostructure is a promising photocatalyst in overall water splitting.