High KRT17 expression in tumour budding indicates immunologically 'hot' tumour budding and predicts good survival in patients with colorectal cancer

Objectives

Emerging evidence has demonstrated that tumour budding (TB) is negatively associated with T-lymphocyte infiltration in CRC. Despite extensive research, the molecular characteristics of immunologically 'hot' TB remain poorly understood.

Methods

We quantified the number of TB by haematoxylin-eosin (H&E) sections and the densities of CD3+ and CD8+ T-lymphocytes by immunohistochemistry in a CRC cohort of 351 cases who underwent curative resection. We analysed the differential expression and T-lymphocyte infiltration score of 37 human epithelial keratins in CRC using RNA sequencing from the TCGA dataset. In 278 TB-positive cases, KRT17 expression was evaluated in tumour centre (TC) and TB with a staining score. Patient demographic, clinicopathological features and survival rates were analysed.

Results

In a CRC cohort of 351 cases, low-grade TB was associated with high CD3+ and CD8+ T-cell densities in the invasive margin (IM) but not in the TC. Of 37 human epithelial keratins, only KRT17 expression in TB had an apparent association with TB-grade and T-lymphocyte infiltration. In 278 TB-positive cases, high KRT17 expression in TB (KRT17TB) was negatively associated with low-grade TB and positively associated with high CD3+ and CD8+ T-cell densities in IM. High KRT17TB predicted early tumour grade, absence of lymph node metastasis and absence of tumour deposits. Additionally, patients with high KRT17TB had good overall survival and disease-free survival. Notably, low KRT17TB can specifically identify those patients with a poor prognosis among colorectal cancer patients with low TB and high T-lymphocyte infiltration.

Conclusions

KRT17 can be employed as a new indicator for distinguishing different immunological TBs.

KRT17 promotes T-lymphocyte infiltration through the YTHDF2-CXCL10 axis in colorectal cancer

Poor infiltration of T lymphocytes has been regarded as a crucial mechanism of tumor immune escape. Here, we demonstrate a protective role of KRT17 in colorectal cancer (CRC), where KRT17 reversed the tumor immunosuppressive microenvironment by increasing T-lymphocyte infiltration. High-throughput RNA sequencing suggested KRT17 was significantly upregulated in deficient mismatch repair (dMMR) tumors compared to proficient mismatch repair (pMMR) tumors. In a CRC cohort of 446 cases, KRT17 expression positively correlated with better clinical outcomes. Krt17 overexpression decreased xenograft tumor growth in immune-competent mice. T-cell depletion in a murine model showed that the presence of T lymphocytes was necessary for Krt17-mediated disruption of tumorigenesis. Mass spectrometry and co-immunoprecipitation assays suggested KRT17 caused YTHDF2 degradation through the ubiquitin-proteasome system. Through high-throughput RNA immunoprecipitation sequencing, we found CXCL10 was the target gene of the N6-methyladenosine (m6A) 'reader' YTHDF2. KRT17 synergized with anti-PD-1 for better tumor control in an immunotherapy-resistant murine model. In a cohort of patients with CRC receiving pembrolizumab, high KRT17 expression was found within the tumors of responders. Collectively, we elucidated a critical role of KRT17 in CRC to prevent immune escape. These findings present new insights into potential therapeutic strategies and effective markers of immunotherapy reactivity against pMMR tumors.

Engulfment and cell motility protein 1 fosters reprogramming of tumor-associated macrophages in colorectal cancer

Functional reprogramming of tumor-associated macrophages (TAMs) is crucial to their potent tumor-supportive capacity. However, the molecular mechanism behind the reprogramming process remains poorly understood. Here, we identify engulfment and cell motility protein 1 (ELMO1) as a crucial player for TAM reprogramming in colorectal cancer (CRC). The expression of ELMO1 in stromal but not epithelial tumor cells was positively associated with advanced clinical stage and poor disease-free survival in CRC. An increase in ELMO1 expression was specifically found in TAMs, but not in other multiple nonmalignant stromal cells. Gain- and loss-of-function assays indicated ELMO1 reprogrammed macrophages to a TAM-like phenotype through Rac1 activation. In turn, ELMO1-reprogrammed macrophages were shown to not only facilitate the malignant behaviors of CRC cells but exhibited potent phagocytosis of tumor cells. Taken together, our work underscores the importance of ELMO1 in determining functional reprogramming of TAMs and could provide new insights on potential therapeutic strategies against CRC.

Three-year outcomes of transanal total mesorectal excision versus standard laparoscopic total mesorectal excision for mid and low rectal cancer

INTRODUCTION

Since transanal total mesorectal excision (taTME) was introduced, it has become an important topic in rectal cancer treatment. Many previous studies reported positive relevant short-term results, histopathological results, and associated complications. Recently, concerns regarding the oncological safety of taTME have been raised due to reports showing high local recurrences (LR) rates. Therefore, this study aimed to compare the 3-year outcomes between taTME and laparoscopic total mesorectal excision (laTME) for mid-low rectal cancer.

METHODS

A total of 104 patients who underwent taTME were matched with 208 patients treated by laTME. The primary endpoint was 3-year LR rate; secondary endpoints in this matched-cohort study included the perioperative outcomes and histopathological outcomes.

RESULTS

taTME was associated with lower permanent ostomy rate (1% vs 13.5%) and lower conversion rate (0% vs 3.4%) compared to laTME. A similar quality of resected specimens was detected for each group. In both groups, the local recurrence rate was 3.8%. Within 3 years after surgery, the disease-free survival (DFS) rates were 78.8% in the taTME group and 76.9% in the laTME group (P = 0.640), while the overall survival (OS) rates were 93.3% in the taTME group and 89.9% in the laTME group (P = 0.327).

CONCLUSION

No significant differences regarding 3-year local recurrence rate (3.8%) were observed in the taTME group compared to laTME group.

A Positive Feedback Loop between Inactive VHL-Triggered Histone Lactylation and PDGFRβ Signaling Drives Clear Cell Renal Cell Carcinoma Progression

Inactive von Hippel-Lindau (VHL) is linked to metabolic reprogramming and plays pivotal roles in the pathogenesis of clear cell renal cell carcinoma (ccRCC). Here, we identify a previously unknown oncogenic role for inactive VHL in actively triggering histone lactylation to promote ccRCC progression. In patients with ccRCC, inactive VHL positively correlates with the presence of histone lactylation, and high levels of histone lactylation indicates poor patient prognosis. Inactive VHL-triggered histone lactylation contributes to ccRCC progression by activating the transcription of platelet-derived growth factor receptor β (PDGFRβ). In turn, PDGFRβ signaling is shown to stimulate histone lactylation, thereby forming an oncogenic positive feedback loop in ccRCC. Target correction of aberrant histone lactylation represses the growth and metastasis of ccRCC in vivo. More importantly, the combined inhibition of histone lactylation and PDGFRβ significantly reinforces the therapeutic efficacy. This work underscores the importance of histone lactylation in facilitating ccRCC progression and suggests targeting the positive feedback loop between histone lactylation and PDGFRβ signaling might provide a promising therapeutic strategy for ccRCC patients.

Amino acid composition of royal jelly harvested at different times after larval transfer

The amino acids in royal jelly (RJ) have a wide range of pharmacological and health-promoting functions in humans. Multiple studies on the amino acid quality and composition in RJ have investigated RJ harvested at 72 h after larval transfer. In contrast, the concentration of amino acids in RJ harvested before 72 h remains unknown. In this study, the concentration of free amino acids (FAAs) and total amino acids (TAAs) in RJ harvested at 13 time points between 24 and 72 h after transfer of ten Apis mellifera colonies were measured. Our results indicated that the most abundant FAAs were Pro, Phe, Lys, Glu, and Tyr, whereas the most abundant TAAs were Asp, Glu, Leu, Lys, and Val. The total FAA concentration in RJ increased with increasing harvest time, from 4.30 mg/g at 24 h to 9.48 mg/g at 72 h. In contrast, the variation in concentration of TAAs observed was a decrease-increase-decrease trend with 40 h (149.53 mg/g) and 52 h (169.62 mg/g) as inflection points. The highest and lowest concentrations of TAA were 197.96 and 121.32 mg/g at 24 and 72 h, respectively. To our knowledge, this is the first study to investigate the concentration changes of FAAs and TAAs prior to 72 h after transfer. Our results will provide theoretical support to guide production practices of beekeeping, as well as elucidate the relationship between the harvest time point and RJ content.

Molecular cloning and evolutionary analysis of captive forest musk deer bitter taste receptor gene T2R16

Sensing bitter tastes is crucial for most animals because it can prevent them from ingesting harmful food. This process is mainly mediated by the bitter taste receptors (T2R) that are largely expressed in the taste buds. Previous studies have identified some T2R gene repertoires. Marked variation in repertoire size has been noted among species. However, research on T2Rs is still limited and the mechanisms underlying the evolution of vertebrate T2Rs remain poorly understood. In the present study, we analyzed the structure and features of the protein encoded by the forest musk deer (Moschus berezovskii) T2R16 and submitted the gene sequence to NCBI GenBank. The results showed that the full coding DNA sequence (CDS) of musk deer T2R16 (GenBank accession No. KP677279) was 906 bp, encoding 301 amino acids, which contained ATG start codon and TGA stop codon, with a calculated molecular weight of 35.03 kDa and an isoelectric point of 9.56. The T2R16 protein receptor had seven conserved transmembrane regions. Hydrophobicity analysis showed that most amino acid residues in T2R16 protein were hydrophobic, and the grand average of hydrophobicity (GRAVY) was 0.657. Phylogenetic analysis based on this gene revealed that forest musk deer had the closest association with sheep (Ovis aries), as compared to cow (Bos taurus), Tursiops truncatus, and other species, whereas it was genetically farthest from humans (Homo sapiens). We hope these results would complement the existing data on T2R16 and encourage further research in this respect.

Avian sarcoma and leukosis virus gag gene in the Anser anser domesticus genome

Endogenous retroviruses are regarded as ideal genetic markers for evolutionary analyses. Birds were some of the initial vertebrates found to contain endogenous retroviruses. However, few studies have investigated the presence and distribution of endogenous retroviruses in goose. In this study, we detected the avian sarcoma and leukosis virus gag gene in the genomic DNA of 8 Chinese native breeds using polymerase chain reaction method. The results indicated that a 1.2-kb avian sarcoma and leukosis virus gag sequence was integrated into all 8 goose breeds. The mean genetic pairwise distance was 0.918% among the investigated geese. To the best of our knowledge, this is the first report demonstrating the presence of the endogenous retroviruses in the domestic goose genome. The genetic structure should be further examined in the domestic goose.

Cochlear protection against cisplatin by viral transfection of X-linked inhibitor of apoptosis protein across round window membrane

We have previously demonstrated that both age-related and noise-induced hearing loss are reduced in transgenic mice that ubiquitously overexpress X-linked inhibitor of apoptosis protein (XIAP). In view of the therapeutic implications of these findings, we have developed a minimally invasive surgical method to deliver adenoid-associated virus (AAV) across the round window membrane (RWM) of the cochlea, enabling efficient gene transfer to hair cells and sensory neurons in this enclosed structure. This RWM approach was used in the present study to evaluate the effectiveness of AAV-mediated XIAP overexpression in protecting against cisplatin-induced ototoxicity. Two weeks following surgery, AAV-derived XIAP was detected in the majority of inner and outer hair cells, resulting in a threefold elevation of this antiapoptotic protein in the cochlea. The protection of AAV-mediated XIAP overexpression was evaluated in animals treated with cisplatin at a dose of 4 mg kg(-1) per day for 4-7 consecutive days. The XIAP overexpression was found to attenuate cisplatin-induced hearing loss by ~22 dB. This was accompanied by a reduction of the loss of vulnerable hair cells and sensory neurons in the cochlea by 13%.

Differential expression of Toll-like receptor genes in lymphoid tissues between Marek's disease virus-infected and noninfected chickens

Toll-like receptors (TLR) are trans-membrane sensors recognizing invading microbes. Toll-like receptors play a central role in initiating immune responses against several pathogens. In this study, we investigated the response of TLR and downstream genes to Marek's disease virus (MDV) infection. Forty 1-d-old chicks were randomly divided into 2 groups, with 20 chicks infected with MDV and 20 chicks mock-infected. Four chickens were euthanized respectively from infected and age-matched noninfected groups at 4, 7, 14, 21, and 28 d postinfection (dpi). Bursas, spleens, and thymuses were removed. The differential expression of TLR genes, including TLR3, TLR5, TLR7, TLR15, and TLR21, and downstream genes of TLR7, including MyD88, TRAF3, TRAF6, IFNA, IFNB, and IL6, in lymphoid tissues of MDV-infected and noninfected chickens was determined by real-time PCR. The results showed that the change of TLR genes was different in 3 lymphoid tissues. Expression of TLR7 and MyD88 was upregulated at 14 dpi and downregulated at 28 dpi in MDV-infected compared with noninfected spleens. The TRAF6 and IFNB were upregulated, and TRAF3, IFNA, and IL6 genes showed increasing trends in MDV-infected compared with noninfected spleens at 14 dpi. The expression of TLR3 and TLR15 genes was downregulated in MDV-infected compared with noninfected spleens at 28 dpi. The results indicated that TLR7 and its downstream genes were a response to MDV infection at 14 dpi. However, the function of TLR was impaired when the infection entered the tumor transformation phase. In bursas, TLR3 and TLR15 genes were upregulated at 7 and 4 dpi, respectively. It indicated that TLR3 and TLR15 might be involved in response to MDV infection in bursa at early phases. However, no differential expression of TLR genes was observed between MDV-infected and noninfected thymuses, which indicated that the thymus had little response to MDV infection mediated by TLR.

Differences in the benthic-pelagic particle flux (biodeposition and sediment erosion) at intertidal sites with and without clam (Ruditapes philippinarum) cultivation in eastern China

An annular flume or flux system (AFS) was deployed to measure the biodeposition and sediment resuspension processes at four stations in the mid-shore and low-shore zones along both natural and Manila clam (Ruditapes philippinarum) farming transects in Xuejiadao intertidal area located in Jiaozhou Bay, eastern China. The results showed that there was a significant correlation between biodeposition rates and the density (r=0.984, P<0.05) and biomass (r=0.977, P<0.05) of the suspension feeding Manila clam. The effect of biodeposition at the farming transect was more intensive than at the natural transect where the biodeposition effect was lower than that resulting from natural sedimentation. In contrast, the biodeposition rate at the culture site with the high density of Manila clams was four times the sedimentation rate. Following the addition of Manila clams to increase their density in natural sediments, there was a marked increase in both clearance and biodeposition rates at all four sites. At the site with the highest natural bivalve biomass, the biodeposition rate increased 1.5-fold, while at the site with the least bivalve biomass, it increased by 40 times compared with the biodeposition rate by natural biota. The mean clearance rate of Manila clam was 0.90+/-0.34 l h(-1) ind.(-1) and the biodeposition rate was calculated to be 0.06+/-0.01 g h(-1) ind.(-1). The critical erosion velocities of intertidal sediment at Xuejiadao were from 17.4 to 20.4 cm s(-1). Relationships describing suspended particulate matter (SPM) vs. current velocity were analysed by linear regression following log transformation of the SPM. Statistical analysis of the slopes of the regression lines revealed that there were distinct differences between the low-shore and mid-shore (P<0.05) at both transects, respectively. There was also distinct difference between the two mid-shore stations (P<0.05) possibly due to differences in the densities of bioturbators (e.g. Macoma incongrua etc.), however, there was no significant difference between the two low-shore stations (P>0.05). Furthermore, it was found that the site differences in sediment erodibility were not significantly correlated with measured physical properties of sediments and biota factors such as total macrofauna biomass, total abundance and macrofauna densities, Chl-a and Ph-a (P>0.05). However, there was a significant correlation between sediment erodability and both median grain size (P<0.01) and the density of the bioturbator M. incongrua (P<0.05). There was also evidence of a slight increase in sediment stability after 3 h of air exposure, but the effect was not overcome following the addition of Manila clams. It is hypothesised that the lower stability of sediments at the mid-shore level was probably associated with higher densities of bioturbators and with disturbance by shrimp farming near the high-shore.

The usefulness of Tc-99m HMPAO labeled WBC SPECT in eosinophilic gastroenteritis

Tc-99m HMPAO labeled WBC SPECT was performed in 5 patients with eosinophilic gastroenteritis before and after successful medical therapy. The imaging findings were graded according to the following imaging scheme; grade 0, no uptake; grade 1, uptake < bone marrow; grade 2, uptake < liver; grade 3, uptake > liver. In no patient was the diagnosis made radiologically or with colonoscopy. The sites of involvement were identified with Tc-99m HMPAO WBC imaging in all patients before treatment and the radionuclide imaging studies were all negative after therapy.