Specific Decrease in B-Cell-Derived Extracellular Vesicles Enhances Post-Chemotherapeutic CD8+ T Cell Responses.

Systemic immunosuppression greatly affects the chemotherapeutic antitumor effect. Here, we showed that CD19+ extracellular vesicles (EVs) from B cells through CD39 and CD73 vesicle-incorporated proteins hydrolyzed ATP from chemotherapy-treated tumor cells into adenosine, thus impairing CD8+ T cell responses. Serum CD19+ EVs were increased in tumor-bearing mice and patients. Patients with fewer serum CD19+ EVs had a better prognosis after chemotherapy. Upregulated hypoxia-inducible factor-1α (HIF-1α) promoted B cells to release CD19+ EVs by inducing Rab27a mRNA transcription. Rab27a or HIF-1α deficiency in B cells inhibited CD19+ EV production and improved the chemotherapeutic antitumor effect. Silencing of Rab27a in B cells by inactivated Epstein-Barr viruses carrying Rab27a siRNA greatly improved chemotherapeutic efficacy in humanized immunocompromised NOD PrkdcscidIl2rg-/- mice. Thus, decreasing CD19+ EVs holds high potential to improve the chemotherapeutic antitumor effect.

Multi-parameter Inputted Logic-Gating on Aptamer-Encoded Extracellular Vesicles for Colorectal Cancer Diagnosis.

Extracellular vesicles (EVs) have emerged as a potential biomarker in liquid biopsy. However, cancer heterogeneity poses significant challenge to precise molecular diagnosis based on single-parameter input. Hence, strategies for analyzing multiple inputs with molecular computing were developed with the aim of improving diagnostic accuracy in liquid biopsy. In the present study, based on the surface of aptamer-encoded EVs, three toe-hold extended DNA aptamers served as specific inputs to perform AND-logic-gating to distinguish between healthy and cancerous EVs. In addition, this strategy has been successfully employed to analyze circulating EVs in clinical samples from colorectal cancer patients and healthy donors. The developed method has a promising future in the analysis of multiplex EV membrane proteins and the identification of early cancer.

WISP3 suppresses ESCC progression by inhibiting the IGF-2-IGF1R-AKT signaling cascade.

Esophageal squamous cell carcinoma (ESCC) is a major health problem worldwide, especially in the Chinese population. However, the intrinsic molecular mechanisms of ESCC progression are largely unclear, thus there is an unmet need to identify essential genes governing this disease. Here, we discovered WISP3, an important member of the CCN family, is markedly downregulated in ESCC tissues compared to the normal esophageal epithelium. Downregulation of WISP3 in cancer tissue correlates with worse overall survival of ESCC patients. Using ESCC cell lines as models, we found that forced expression of WISP3 not only suppressed proliferation and migration of cancer cells in vitro, but also inhibited ESCC tumor growth and metastasis in vivo. On the contrary, WISP3 depletion strongly promoted the tumorigenicity of ESCC cells. Mechanistically, we found that WISP3 negates the activity of AKT via inhibiting the IGF-2-IGF1R signaling cascade, which mediates the tumor-suppressive function of WISP3 in esophageal cancers. Together, we identified a novel factor driving the development of ESCC, and revealed a potential therapeutic target for ESCC treatment.

Exosomes from heat-stressed tumour cells inhibit tumour growth by converting regulatory T cells to Th17 cells via IL-6.

Exosomes derived from heat-stressed tumour cells (HS-TEXs), which contain abundant heat shock protein (HSP) 70, strongly induce antitumour immune responses. HSP70-induced interleukin (IL)-6 promotes IL-17 expression and causes rejection of established prostate tumours. However, it remains unclear whether HS-TEXs exhibit antitumour effects by converting regulatory T cells (Tregs ) into T helper type 17 (Th17) cells. In this study, we found that compared with TEXs, HS-TEXs were more potent in stimulating secretion of IL-6 from dendritic cells. In vitro, IL-6 blocked tumour cell-derived transforming growth factor beta 1-induced Treg differentiation and promoted Th17 cell differentiation. HS-TEXs exerted strong antitumour effects, converting Tregs into Th17 cells with high efficiency, a process that was entirely dependent upon IL-6. Neutralization of IL-17 completely abolished the antitumour effect of TEXs, but only partially inhibited that of HS-TEXs. In addition, we found higher levels of IL-6 and IL-17 in serum from tumour patients treated with hyperthermia, and an increase in Th17 cells and a decrease in Tregs was detected in peripheral blood mononuclear cells isolated from these patients after hyperthermia. Therefore, our results demonstrate that HS-TEXs possess a powerful capacity to convert immunosuppressive Tregs into Th17 cells via IL-6, which contributes to their potent antitumour effect.

A near-infrared fluorescent sensor with large Stokes shift for rapid and highly selective detection of thiophenols in water samples and living cells.

The development of simple methods with high sensitivity and selectivity to differentiate toxic aromatic thiols (thiophenols) from aliphatic thiols (cysteine, homocysteine, and glutathione) and hydrogen sulfide (H2S) is of great significance. Herein, we report on the fabrication of a novel near-infrared (NIR) fluorescent sensor for rapid and highly selective detection of thiophenols through the photoinduced electron transfer (PET) mechanism. In the presence of the thiophenols, an obvious enhancement of NIR fluorescence at 658 nm could be visualized with the aid of nucleophilic aromatic substitution (SNAr) reaction. The sensor displays large Stokes shift (~ 227 nm), fast response time (< 30 s), high sensitivity (~ 8.3 nM), and good biocompatibility. Moreover, the as-prepared sensor possesses an excellent anti-interference feature even when other possible interferents exist (aliphatic thiols and H2S) and has been successfully utilized for thiophenol detection in both water samples and living cells. Graphical abstract Illustration of the sensor for thiophenol imaging in living cells.

Increased anti-tumour activity by exosomes derived from doxorubicin-treated tumour cells via heat stress.

PURPOSE: Tumour-cell-derived exosomes (Exo) have been proposed as a new kind of drug carrier, and heat stress can promote release of exosomes from tumour cells. This study investigated the impact of heat stress on the quantity of doxorubicin in exosomes from the same number of doxorubicin-treated MFC-7 tumour cells and their anti-tumour effects. MATERIALS AND METHODS: Exosomes were isolated from phosphate-buffered saline (Exo), doxorubicin (Exo-Dox) or doxorubicin combined with heat-stress-treated (Exo-Dox-HS) MCF-7 cells. The content of doxorubicin in the exosomes was determined by flow cytometry. The effects of individual types of exosomes on the MCF-7 cell proliferation and apoptosis as well as the tumour growth were determined by MTT assay, flow cytometry and murine xenograft tumour modelling. RESULTS: We found that the amount of Exo-Dox-HS was higher than that of Exo-Dox from the same number of MCF-7 cells, and Exo-Dox-HS contained higher levels of doxorubicin than Exo-Dox from the same number of cells. Exo-Dox and Exo-Dox-HS, but not Exo or 10 µg/mL doxorubicin, significantly inhibited the MCF-7 cell proliferation and triggered MCF-7 cell apoptosis, associated with increased levels of cleaved caspase-3 and -8 and morphological changes in MCF-7 cells. Treatment with Exo-Dox and Exo-Dox-HS inhibited the growth of implanted breast tumours in mice. CONCLUSIONS: Our study indicated that heat stress increased the quantity of doxorubicin-containing exosomes from tumour cells, and enhanced the anti-tumour effect of exosomes from the doxorubicin-treated tumour cells. Our findings may aid in designing new strategies for cancer therapy by combination of chemotherapy and hyperthermia.

Activated T cell exosomes promote tumor invasion via Fas signaling pathway.

Activated T cells release bioactive Fas ligand (FasL) in exosomes, which subsequently induce self-apoptosis of T cells. However, their potential effects on cell apoptosis in tumors are still unknown. In this study, we purified exosomes expressing FasL from activated CD8(+) T cell from OT-I mice and found that activated T cell exosomes had little effect on apoptosis and proliferation of tumor cells but promoted the invasion of B16 and 3LL cancer cells in vitro via the Fas/FasL pathway. Activated T cell exosomes increased the amount of cellular FLICE inhibitory proteins and subsequently activated the ERK and NF-κB pathways, which subsequently increased MMP9 expression in the B16 murine melanoma cells. In a tumor-invasive model in vivo, we observed that the activated T cell exosomes promoted the migration of B16 tumor cells to lung. Interestingly, pretreatment with FasL mAb significantly reduced the migration of B16 tumor cells to lung. Furthermore, CD8 and FasL double-positive exosomes from tumor mice, but not normal mice, also increased the expression of MMP9 and promoted the invasive ability of B16 murine melanoma and 3LL lung cancer cells. In conclusion, our results indicate that activated T cell exosomes promote melanoma and lung cancer cell metastasis by increasing the expression of MMP9 via Fas signaling, revealing a new mechanism of tumor immune escape.

Ceftazidime is a potential drug to inhibit cell proliferation by increasing cellular p27.

The development of new therapeutic uses for existing drugs is important for the treatment of some diseases. Cephalosporin antibiotics stand as the most extensively utilized antibiotics in clinical practice, effectively combating bacterial infections. Here, we found that the antimicrobial drug ceftazidime strongly upregulates p27 protein levels by inhibiting p27 ubiquitination. The p27 protein is a classic negative regulator of the cell cycle. Next, we demonstrated that ceftazidime can impede the cell cycle from G1 to S phase, thus inhibiting cell proliferation. Furthermore, we found that ceftazidime promotes p27 expression and inhibits cell proliferation by reducing Skp2, which is a substrate recognition component of the Skp2-Cullin-F-box (SCF) ubiquitin ligase. Moreover, ceftazidime downregulates transcriptional expression of Skp2. Importantly, we demonstrated that ceftazidime inhibited the proliferation of tumor cells in vivo. These findings reveal ceftazidime-mediated inhibition of cell proliferation through the Skp2-p27 axis, and could provide a potential strategy for anti-tumor therapy.

Immune checkpoint inhibitors combined with paclitaxel-based chemotherapy versus chemotherapy alone as first-line treatment in HER2-negative advanced gastric cancer: result of a multicenter retrospective study.

Background: Platinum-based chemotherapy combined with immune checkpoint inhibitors (ICIs) is now becoming the standard first-line therapy for human epidermal growth factor receptor 2 (HER2)-negative advanced gastric cancer (AGC). In China, paclitaxel has shown good efficacy and tolerability in AGC as an alternative for first-line therapy. Combining ICIs with paclitaxel-based chemotherapy may lead to improved tumor immune microenvironment, but evidence in paclitaxel combing with ICIs as first-line regimen is lacking. This multicenter, retrospective research aims to compare effectiveness and tolerability of paclitaxel-based chemotherapy combined with ICIs versus chemotherapy alone as a first-line treatment of HER2-negative AGC in a real-world setting. Methods: Eighty-six patients with HER2-negative AGC were included from 2017 to 2022. Among them, 57 patients received paclitaxel-based chemotherapy plus ICIs, and 29 patients received paclitaxel-based chemotherapy alone. We compared the efficacy and incidence of adverse events between the two therapy options. Results: Significant improvements in median progression-free survival (PFS) (8.77 versus 7.47 months; P=0.04) and median overall survival (OS) (15.70 versus 14.33 months; P=0.04) were observed in the ICIs combined with paclitaxel-based chemotherapy group. The use of ICIs also significantly prolonged the duration of response (DOR) (7.47 versus 4.59 months; P=0.02). Meanwhile, the ICIs plus chemotherapy group demonstrated significantly improved objective response rate (ORR) (50.9% vs. 27.6%; P=0.03) and disease control rate (DCR) (98.3% vs. 82.8%; P=0.01), and the side effects were tolerable. Conclusions: In summary, for HER2-negative AGC, ICIs plus paclitaxel-based chemotherapy is effective with mild toxicities, which should be considered as an alternative first-line therapy regimen.

Study of treatment using percutaneous acetabuloplasty and interstitial implantation of (125)I seeds for patients with metastatic periacetabular tumors.

BACKGROUND: The periacetabular area is one of the primary sites of metastatic tumors, which often present as osteolytic bone destruction. Bone destruction in the acetabulum caused by metastatic tumors will cause hip pain and joint dysfunction. It results in decreased quality of life for patients. The aim of our study was to explore the clinical effect of metastatic periacetabular tumors treated with percutaneous cementoplasty and interstitial implantation of (125)I seeds. METHODS: A retrospective analysis was performed on 24 patients with metastatic periacetabular tumors who underwent combined therapy of percutaneous acetabuloplasty and interstitial implantation of (125)I seeds between February 2003 and June 2011. There were 13 males and 11 females aged 19-80 years with a mean age of 57.3. The primary tumor site was the lung in eight cases, the breast in six, the prostate cancer in eight, and the liver in two. The amount of implanted (125)I seeds was 12-20 seeds/person, with a mean of 16.5 seeds/person, and the matching peripheral dosage (MPD) was 80~100Gy. Routine postoperative chemotherapy and other combined treatments were applied to patients after the surgical operation. Changes in the Karnofsky Score(KPS), Harris Hip Score(Harris), and Visual Analog Scale(VAS) were observed during the follow-up period. RESULTS: The 24 patients' operations were all successful. No major complications occurred. Complete pain relief was achieved in 58% (14 of 24) of patients, and pain reduction was achieved in the 42% remaining (10) patients. The mean duration of pain relief was 8.3 months. Pain recurred in one patient 3 months after surgery. Six patients had died and 18 patients were alive at the time of the 1-year follow-up. Comparing the KPS, Harris and VAS scores pre- and postoperativelyat 1, 6, and 12 months, the combined therapy method was significantly effective in metastatic periacetabular tumor patients (P<0.05). CONCLUSIONS: Percutaneous cementoplasty with interstitial implantation of (125)I seeds is an effective treatment method for metastatic periacetabular tumor patients, providing tumor resistance, pain relief, increased bone stability, and improved quality of life for patients.

Quantitative Relationship Between Solar Radiation and Grain Filling Parameters of Maize.

A quantitative understanding of the factors driving changes in grain filling is essential for effective prioritization of increasing maize yield. Grain filling is a significant stage in maize yield formation. Solar radiation is the energy source for grain filling, which is the ultimate driving factor for final grain weight and grain filling capacity that determine maize yield. Here, we first confirmed the quantitative relationships between grain filling parameters and photosynthetically active radiation (PAR) by conducting field experiments using different shading and plant density conditions and cultivars in 2019 and 2020 in Xinjiang, China. The results showed that with every 100 MJ m-2 increase in PAR, the average grain filling rate (G ave), maximum grain-filling rate (G max), and the kernel weight at the time of maximum grain-filling rate (W max) increased by 0.073 mg kernel-1 day-1, 0.23 mg kernel-1 day-1, and 0.24 mg kernel-1, and the time of maximum grain-filling rate (T max) delayed by 0.91 day. Relative changes in PAR were significantly and positively correlated with relative changes in yield and G ave. With every 1% change in PAR, yield and G ave changed by 1.16 and 0.17%, respectively. From the perspective of grain filling capacity, DH618 was a more shade-resistant cultivar than XY335 and ZD958. It is urgent to breed maize cultivars with low light tolerance and high grain yield in the face of climate change, particularly the decrease in solar radiation.

Gp350-anchored extracellular vesicles: promising vehicles for delivering therapeutic drugs of B cell malignancies.

Although chimeric antigen receptor-modified (CAR) T cell therapy has been successfully applied in the treatment of acute B lymphocytic leukemia, its effect on Burkitt lymphoma (BL) and chronic B lymphocytic leukemia (B-CLL) is unsatisfactory. Moreover, fatal side effects greatly impede CAR T cell application. Extracellular vesicles (EVs) are excellent carriers of therapeutic agents. Nevertheless, EVs mainly accumulate in the liver when administered without modification. As an envelope glycoprotein of Epstein-Barr viruses, gp350 can efficiently bind CD21 on B cells. Here, gp350 was directly anchored onto red blood cell EVs (RBC-EVs) via its transmembrane region combined with low-voltage electroporation. The results showed that gp350 could anchor to RBC-EVs with high efficiency and that the resulting gp350-anchored RBC-EVs (RBC-EVs/gp350Etp) exhibited increased targeting to CD21+ BL and B-CLL relative to RBC-EVs. After the loading of doxorubicin or fludarabine, RBC-EVs/gp350Etp had powerful cytotoxicity and therapeutic efficacy on CD21+ BL or B-CLL, respectively. Moreover, RBC-EVs/gp350Etp loaded with a drug did not exhibit any apparent systemic toxicity and specifically induced the apoptosis of tumor B cells but not normal B cells. Therefore, our findings indicate that drug-loaded RBC-EVs/gp350Etp may be adopted in the treatment of CD21+ B cell malignancies.

Menthone inhibits type-I interferon signaling by promoting Tyk2 ubiquitination to relieve local inflammation of rheumatoid arthritis.

Rheumatoid arthritis (RA) is an inflammatory autoimmune disease. RA development is mediated by the abnormal activation of multiple signaling pathways. Recent studies have revealed that type-I interferon (IFN-I) signaling plays an essential role in the occurrence and development of RA. However, how to target IFN-I signaling to develop anti-rheumatoid arthritis drugs remains largely unexplored. Here, our study showed that IFN-I signaling was over-activated in articular synovial cells from collagen II-induced arthritis (CIA) mice. Interestingly, we found that a small molecule compound, menthone, strongly inhibited the activation of the IFN-I signaling pathway. Further studies revealed that menthone promoted K48-linked polyubiquitination of Tyk2, thus lowering the protein level and stability of Tyk2. Importantly, menthone administration in the local articulus of CIA mice significantly attenuated the local inflammation in CIA mice. This study could promote our understanding of rheumatoid arthritis, and also suggests a potential strategy to develop anti-RA drugs.

Induction of a tumour-specific CTL response by exosomes isolated from heat-treated malignant ascites of gastric cancer patients.

PURPOSE: Tumour cell-derived exosomes may represent a novel type of cancer vaccine. However, the immunogenicity of exosomes derived from tumour cells has been shown to be poor. Therefore, in this study, exosome immunogenicity following heat treatment of exosomes from malignant ascites obtained from gastric cancer patients was evaluated. MATERIALS AND METHODS: Tumour-derived exosomes were isolated from heat-treated and untreated malignant ascites of gastric cancer patients using serial centrifugation and sucrose gradient ultracentrifugation. Next, in vitro experiments were performed to investigate the influence of heat treatment on exosome immunogenicity. RESULTS: Exosomes from heat-treated malignant ascites of gastric cancer patients (HS exosomes) were found to contain higher concentrations of heat shock proteins, Hsp70 and Hsp60, than exosomes derived from untreated malignant ascites obtained from gastric cancer patients. Additional in vitro studies suggest that exosomes derived from heat-treated malignant ascites are able to promote dendritic cell (DC) maturation and induce a tumour-specific cytotoxic T lymphocyte (CTL) response. CONCLUSIONS: Overall, these results demonstrate that exposure to heat stress can improve the immunogenicity of exosomes obtained from malignant ascites of gastric cancer patients.

Solar Radiation Effects on Dry Matter Accumulations and Transfer in Maize.

Solar radiation is the energy source for crop growth, as well as for the processes of accumulation, distribution, and transfer of photosynthetic products that determine maize yield. Therefore, learning the effects of different solar radiation amounts on maize growth is especially important. The present study focused on the quantitative relationships between solar radiation amounts and dry matter accumulations and transfers in maize. Over two continuous years (2017 and 2018) of field experiments, maize hybrids XY335 and ZD958 were grown at densities of 4.5 × 104 (D1), 7.5 × 104 (D2), 9 × 104 (D3), 10.5 × 104 (D4), and 12 × 104 (D5) plants/ha at Qitai Farm (89°34'E, 44°12'N), Xinjiang, China. Shading levels were 15% (S1), 30% (S2), and 50% (S3) of natural light and no shading (CK). The results showed that the yields of the commonly planted cultivars XY335 and ZD958 at S1, S2, and S3 (increasing shade treatments) were 7.3, 21.2, and 57.6% and 11.7, 31.0, and 61.8% lower than the control yields, respectively. Also, vegetative organ dry matter translocation (DMT) and its contribution to grain increased as shading levels increased under different densities. The dry matter assimilation amount after silking (AADMAS) increased as solar radiation and planting density increased. When solar radiation was <580.9 and 663.6 MJ/m2, for XY335 and ZD958, respectively, the increase in the AADMAS was primarily related to solar radiation amounts; and when solar radiation was higher than those amounts for those hybrids, an increase in the AADMAS was primarily related to planting density. Photosynthate accumulation is a key determinant of maize yield, and the contributions of the vegetative organs to the grain did not compensate for the reduced yield caused by insufficient light. Between the two cultivars, XY335 showed a better resistance to weak light than ZD958 did. To help guarantee a high maize yield under weak light conditions, it is imperative to select cultivars that have great stay-green and photosynthetic efficiency characteristics.

Endogenous human CaMKII inhibitory protein suppresses tumor growth by inducing cell cycle arrest and apoptosis through down-regulation of the phosphatidylinositide 3-kinase/Akt/HDM2 pathway.

Inhibition of calcium/calmodulin-dependent protein kinase II (CaMKII) results in hypophosphorylation of CaMKII substrates and in some cases suppresses cell growth. We previously presented the first report of the human CaMKII inhibitory protein, hCaMKIINbeta. Here we report the functional characterization of hCaMKIINbeta in ovarian cancer cells. We showed that hCaMKIINbeta was highly expressed in normal ovarian tissues but was not detected in human ovarian adenocarcinoma, indicating that decreased expression of hCaMKIINbeta may be involved in the pathogenesis of human ovarian adenocarcinoma. As an endogenous CaMKII inhibitor, hCaMKIINbeta could significantly inhibit the growth of human ovarian cancer cells in vitro. In vivo, hCaMKIINbeta decreased the tumorigenicity and growth of HO-8910PM human ovarian cancer cells and prolonged the survival of tumor-bearing mice. hCaMKIINbeta blocked cell cycle progression and induced apoptosis of HO-8910PM cells, which was correlated with the up-regulation of p21, p53, and Bax and the down-regulation of cyclin A, cyclin D1, cyclin E, CDK2, phosphorylated retinoblastoma, and Bcl-2. We further demonstrated that hCaMKIINbeta-mediated CaMKII inhibition suppressed Akt activation, leading to the down-regulation of HDM2, which was responsible for the up-regulation of p53 and p21 in human ovarian cancer cells. The tumor-suppressive effect and the negative expression in human ovarian cancer tissues suggest that hCaMKIINbeta may play an important role in the regulation of tumor cell growth, possibly contributing to the development of new therapeutic strategies for ovarian cancer.

Correction to: Surface anchorage of superantigen SEA promotes induction of specific antitumor immune response by tumor-derived exosomes.

The corrected Fig. 1 image and caption is presented in this paper.

ST6GAL2 Downregulation Inhibits Cell Adhesion and Invasion and is Associated with Improved Patient Survival in Breast Cancer.

OBJECTIVE: Breast cancer is one of the most common and serious types of cancer, with a particularly unfavorable prognosis. Although dysregulation of ß-galactoside α 2,6-sialyltransferase 2 (ST6GAL2) has been observed in multiple cancers, the mechanism involved remains to be clarified. In this study, we focused on the potential function of ST6GAL2 in the regulation of breast cancer. METHODS: Flow cytometry and CCK-8 were used to measure markers of the cell cycle proliferation, adhesion, and invasion. Real-time PCR and immunohistochemistry analysis were used to detect the expression levels of ST6GAL2 in breast cancer tissues. Western blot was used to analyze the expression level of genes correlated with focal adhesion and metastasis pathways in breast cancer cells. RESULTS: ST6GAL2 expression levels were higher in breast cancer tissues as compared to healthy tissues. ST6GAL2 expression was associated with tumor stage, survival time, and estrogen receptor (ER)/progesterone receptor (PR)/human epidermal growth factor receptor 2 (HER2) status of breast cancer patients. Silence of ST6GAL2 inhibited cancer progression by arresting cell cycle progression at G0/G1 phase and inhibiting cell adhesion and invasion. ST6GAL2 was positively correlated with focal adhesion and metastasis pathways, and its downregulation inhibited the expression of ICAM-1, VCAM-1, CD24, MMP2, MMP9, and CXCR4. CONCLUSION: These findings indicated that ST6GAL2 might serve as a useful potential target for treatment of breast cancer.

Marginal superiority of maize: an indicator for density tolerance under high plant density.

Marginal superiority is a common phenomenon in crops, and is caused by the competitiveness of individual plant for resources and crop adaptability to crowded growth conditions. In this study, in order to clarify the response of marginal superiority to maize morphology and plant-density tolerance, field experiments without water and nutrition stress were conducted at Qitai Farm in Xinjiang, China, in 2013-2014 and 2016-2019. The results showed that no more than three border rows of all the cultivars had marginal superiority under high density, about 90% of all the cultivars had no more than two border row that had marginal superiority and a significant negative correlation was observed between marginal superiority and population grain yield (first border row: y = - 2.193x + 213.9, p < 0.05; second border row: y = - 2.076x + 159.2, p < 0.01). Additionally, marginal superiority was found to have a significant positive relationship with plant density (first border row: y = 6.049x + 73.76, p < 0.01; second border row: y = 1.88x + 95.41, p < 0.05) and the average leaf angle above the ear (first border row: y = 2.306x + 103.1, p < 0.01). These results indicated that the smaller the leaf angle above the ear, the weaker the marginal superiority and the higher the grain yield. It suggests that the magnitude of marginal superiority in the border rows can be an indicator for plant-density tolerance under high density. What's more, cultivars with small leaf angle above the ear can be selected to weaken the marginal superiority and improve grain yield under high plant density. Conversely, cultivars with a large leaf angle above the ear can be selected to achieve higher individual yield in intercropping systems with no more than four rows alternated with other crops.