Synthetic Gene Circuit-Based Assay with Multilevel Switch Enables Background-Free and Absolute Quantification of Circulating Tumor DNA

Circulating tumor DNA (ctDNA) detection has found widespread applications in tumor diagnostics and treatment, where the key is to obtain accurate quantification of ctDNA. However, this remains challenging due to the issue of background noise associated with existing assays. In this work, we developed a synthetic gene circuit-based assay with multilevel switch (termed CATCH) for background-free and absolute quantification of ctDNA. The multilevel switch combining a small transcription activating RNA and a toehold switch was designed to simultaneously regulate transcription and translation processes in gene circuit to eliminate background noise. Moreover, such a multilevel switch-based gene circuit was integrated with a Cas9 nickase H840A (Cas9n) recognizer and a molecular beacon reporter to form CATCH for ctDNA detection. The CATCH can be implemented in one-pot reaction at 35 °C with virtually no background noise, and achieve robust absolute quantification of ctDNA when integrated with a digital chip (i.e., digital CATCH). Finally, we validated the clinical capability of CATCH by detecting drug-resistant ctDNA mutations from the plasma of 76 non-small cell lung cancer (NSCLC) patients, showing satisfying clinical sensitivity and specificity. We envision that the simple and robust CATCH would be a powerful tool for next-generation ctDNA detection.

Up-Regulation of TCF21 Expression Reverses the Malignant Phenotype of Cancer-Associated Fibroblasts in Esophageal Squamous Cell Carcinoma

PURPOSE/OBJECTIVE(S)

Cancer-associated fibroblasts (CAFs), as one major component of tumor microenvironment (TME), are closely associated with tumor initiation and progression. Our previous studies have discovered that CAFs induced the resistance of esophageal squamous cell carcinoma (ESCC) cells to a variety of chemotherapeutic drugs such as cisplatin and paclitaxel. Furthermore, CAFs attenuated ionizing irradiation (IR)-induced cancer cells death by regulating DNA damage response. CAFs themselves are highly resistant to death stimuli due to enhanced antioxidant potential and DNA repair capacity. How to inhibit the malignant phenotype of CAFs is critically important for the radical treatment of ESCC.

MATERIALS/METHODS

By RNA-sequencing and DNA methylation analysis, the transcriptome and epigenome of CAFs and matched normal fibroblasts (NFs) have been integratively analyzed. By transfection of TCF21 cDNA plasmid, the expression of TCF21 in CAFs has been up-regulated. Using a cell counting kit and migration and invasion assay, the effect of TCF21 on the growth and migration and invasive ability of CAFs has been detected. Using immunofluorescence and flow cytometry (FCM) analysis and western blotting, the effect of TCF21 on the DNA damage repair and apoptotic death of CAFs following IR has been detected.

RESULTS

TCF21 is one of the top ten down-regulated genes in CAFs compared with NFs due to promoter methylation. Up-regulation of TCF21 expression inhibited the growth rate and migration and invasive ability of CAFs. The expression of α-SMA, as an indicator of CAFs activation, was down-regulated in CAFs which were transfected with TCF21 cDNA. Furthermore, when TCF21 cDNA was transfected into CAFs, IR-induced DNA damage was increased while DNA repair was inhibited in CAFs, suggesting that TCF21 was involved in DNA damage response of CAFs following IR. FCM analysis showed that up-regulation of TCF21 expression promoted IR-induced apoptotic death of CAFs.

CONCLUSION

TCF21 is a determinant of the malignant phenotype of CAFs in ESCC. Up-regulation of TCF21 expression is a promising approach of inhibiting the growth, migration and invasion, activation and radioresistance of CAFs in ESCC.

Comparison of Pathologic Response and Survival Outcomes between Neoadjuvant Immunochemotherapy (nICT) and Neoadjuvant Chemoradiotherapy (nCRT) in Patients with Locally Advanced Esophageal Squamous Cell Carcinoma: A Propensity Score-Matched Analysis

PURPOSE/OBJECTIVE(S)

The neoadjuvant immunochemotherapy (nICT) is a novel treatment, which is likely to be safer for locally advanced, surgically resectable Esophageal squamous cell carcinoma (ESCC) that comparing with the traditional neoadjuvant therapy. However, the efficacy of nICT was controversial and the survival benefit remain unknown.

MATERIALS/METHODS

This study included 313 patients with locally advanced ESCC who underwent surgery following neoadjuvant therapy at Sichuan Cancer Hospital from June 2017 and September 2021. The patients were divided into nICT group and neoadjuvant chemoradiotherapy (nCRT) group according to the neoadjuvant strategy. A 1:2 propensity score matching (PSM) was used to balance potential bias across several covariates between two groups with a caliper 0.05.

RESULTS

Among the 146 patients after PSM, the baseline factors were comparable between two groups. Compared with the nCRT group, the nICT group shown a lower pathologic complete response(pCR) rate (11.54% vs 35.11%; P = 0.0039) and lymph nodes uninvolved rate (ypN0: 44.23% vs 62.77%; P = 0.0154), but a higher perineural invasion (32.69% vs 12.77%; P = 0.0075) and angioinvasion rate (40.38% vs 10.64%; P = 0.0001). However, the 2-year OS and DFS rates were similar between the nICT group and the nCRT group in overall study cohort, and these data were confirmed in the matched samples (2-year OS, 78.2% vs 77.2% [p = 0.95]; DFS, 56.9% vs 58.0% [p = 0.69]).

CONCLUSION

Our preliminary findings indicate that, for individuals with locally advanced ESCC, nICT followed by surgery appears to be less effective in pathologic outcomes, while having a comparable survival rate to nRCT. These results imply a complicated and possibly multifaceted link between the kind of neoadjuvant therapy, the pathologic outcomes, and the final survival.

Dosimetric Predictors of Acute Diarrhea in Locally Advanced Rectal Cancer Patients Treated with Neoadjuvant Chemoradiation with Capecitabine and Irinotecan: A Discovery and Validation Study

PURPOSE/OBJECTIVE(S)

Additional irinotecan can increase the pCR rate from 15% to 30% compared with capecitabine-based neoadjuvant chemoradiotherapy in locally advanced rectal cancer, while more acute diarrhea was induced and predictors of diarrhea have yet to be fully elucidated. In this analysis, we report the incidence of and factors associated with grade 3+ acute diarrhea in LARC patients treated with the CaplriRT regimen in the CinClare trial.

MATERIALS/METHODS

We identified the dosimetric markers with a lasso-Cox risk scoring model tested on CaplriRT group patients in the CinClare trial at our institution from 2015 to 2017 (CinClare, NCT02605265), and then independently validated according to a predefined protocol in patients treated with neoadjuvant chemoradiation with capecitabine and irinotecan from 2019 to 2022 (NCT05688033). Clinical documentation and patient-reported outcomes were reviewed to determine grade 3+ acute diarrhea events.

RESULTS

A total of 116 patients from Cinclare trial treated with CaplriRT regimen were used as a training cohort to obtain dosimetric prediction model and 168 patients were used for independent validation. The majority received 50 Gray (Gy) in 25 fractions with concurrent capecitabine and irinotecan. Median number of concurrent chemotherapy cycles received was 4 (IQR: 3-4). Seventeen (23.6%) patients treated with the CaplriRT regimen in the CinClare trial experienced grade 3+ acute diarrhea. Dosimetric predictors of acute diarrhea included peritoneal space volume receiving 25 Gy or greater (V25Gy). The single multivariate Cox regression, and receiver operating characteristic (ROC) curve analysis showed that the model had good predictive ability (p<0.05). It was also validated using the validation cohort. Patients with peritoneal space V25Gy>950 cm3 were associated with a higher risk of 3+ acute diarrhea compared with those without constraints of V25Gy (p = 0.002).

CONCLUSION

Peritoneal space V25Gy as an important predictor of acute diarrhea during capecitabine and irinotecan neoadjuvant chemoradiation treatment. Peritoneal space V25Gy < 950 cm3 may reduce acute diarrhea toxicity.

Occult Lymph Node Metastasis in cN0 Tongue Squamous Cell Carcinoma: A Prospective Observational Study

PURPOSE/OBJECTIVE(S)

Tongue squamous cell carcinoma (TSCC) is prone to occult lymph node metastasis, and preoperative evaluation of cervical nodes is critical for determining treatment strategies. There is scarce report of detecting occult lymph node metastasis in TSCC by using multi-parameter magnetic resonance imaging (mpMRI), spectral computed tomography (spectral CT) or other diagnostic functional imaging. In this study, we aimed to analyze the incidence and risk factors of occult lymph node metastasis in cN0 TSCC by comparing preoperative imaging with postoperative pathology results.

MATERIALS/METHODS

This study prospectively enrolled newly-diagnosed cN0 TSCC patients admitted to the Hunan Cancer Hospital between May, 2022 and December, 2022. All patients underwent primary resection and selective dissection of cervical lymph nodes. MpMRI and spectral CT scan of oral cavity and neck were performed prior to surgery. Preoperative evaluation of lymph node metastasis was conducted by two senior radiologists independently. The location of cervical lymph nodes was assigned based on the 2013 consensus guidelines.

RESULTS

A total of 26 cN0 TSCC patients (6 cT1 stage, 13 cT2 stage, and 7 cT3 stage) were enrolled. The median age was 53 (range, 36-64), and there were 25 males. Among all patients, 13 patients underwent unilateral cervical lymph node dissection, while 13 patients underwent bilateral cervical lymph node dissection. A total of 208 lymphatic drainage areas were resected, and 1003 lymph nodes were removed. There were 7 of pT1, 12 of pT2, 7 of pT3 based on postoperative pathological stages. Besides, there are 21 cases staged pN0, 2 cases staged pN1, 2 cases staged pN2, and 1 case staged pN3. Among the 26 patients, 5 (19.23%) cases had occult lymph node metastasis. A total of 8 metastatic lymph nodes (4 in ipsilateral Ib level, 1 in contralateral Ib level, 3 in IIa level ipsilateral side) were detected in the whole group. No lymph node metastasis was detected in level IIb, III and IV. The median maximum diameter of metastatic lymph nodes was 12 mm (range 5 to 15 mm), and 1 extra-nodal extension was observed. Moreover, all occult lymph node metastases occurred in patients with a primary invasion depth of ≥ 5 mm (29.41%, 5/17).

CONCLUSION

The incidence of occult lymph node metastasis in cN0 TSCC remains high under functional imaging diagnostic technology. Preventive neck dissection is necessary for patients with cN0 disease, especially those with primary tumor invasion depth exceeding 5 mm.

Development of a Radiomic Signature from Pre-Treatment FDG-PET for Recurrence Prediction in Cervical Cancer

PURPOSE/OBJECTIVE(S)

As many as 30-50% of patients with locally advanced cervical cancer (LACC) experience recurrence after standard-of-care chemoradiation therapy (CRT), creating a critical need to identify pre-treatment biomarkers of treatment failure. The purpose of this study is to identify whether radiomic features derived from pre-treatment FDG-PET imaging can be used to construct a predictive signature useful for assessing risk of recurrence during treatment planning.

MATERIALS/METHODS

Standardized uptake values (SUV) were obtained from within the physician-defined metabolic tumor volumes (MTV) delineated on FDG-PET scans acquired for 90 LACC patients at our institution prior to standard of care curative-intent CRT. Clinical outcome data of these patients has a median follow-up time of 85 months. The clinical endpoint was local recurrence within 3 years of treatment. 851 quantitative radiomic features describing intensity, shape, texture and high and low frequency spatial filters of the MTV were extracted for each patient. Low information features, defined by pairwise correlation > 0.85 with another feature or a maximum deviation within 20% of the mean, were discarded, leaving 146 features. Predictive signatures were constructed from features using multiple techniques, including multivariate Cox modelling, a set of machine learning models (random forest (RF), support vector classifier (SVC), ridge regression, LASSO regression, and elastic net regression), and a deep neural network (DNN) classifier.

RESULTS

The DNN classifier had the best overall performance, predicting a patient's recurrence group with an F1 score of 0.917 ± 0.028 under 5-fold cross-validation. By contrast, the Cox model classifier yielded an F1 score of 0.604 ± 0.085 and the best performing of the alternative machine learning models, elastic net, yielded F1 score of 0.868 ± 0.018. A set of textural features contributed the most to the output of the DNN classifier, including Large Area Low Gray Level Emphasis of the gray level size zone matrix (GLSZM) and coarseness and busyness of the neighboring gray tone difference matrix (NGTDM), reflecting the important role patterns of tumor heterogeneity play in post-treatment recurrence.

CONCLUSION

In this pilot study, we investigated multiple techniques to construct predictive radiomic signatures for local recurrence in LACC, determining that a DNN classifier is most capable of stratifying patients by risk of early recurrence. Future work will seek to validate this result on additional PET imaging data sets and to integrate radiomic features with gene expression data from matched tumor samples to establish radiogenomic biomarkers for recurrence.

Long-Term Anorectal Function in Rectal Cancer Patients Managed by a Watch-and-Wait Strategy after Neoadjuvant Therapy: A Cross-Sectional Study

PURPOSE/OBJECTIVE(S)

Rectal cancer patients reaching complete clinical response (cCR) after neoadjuvant chemoradiotherapy can be offered a nonoperative watch-and-wait (W&W) strategy. As evidence of good oncological outcomes accumulates, the functional outcomes remain less explored. The aim of this study is to comprehensively assess the long-term rectal toxicity and anorectal function in patients managed by a W&W strategy and to investigate the clinical risk factors for anorectal dysfunction.

MATERIALS/METHODS

Seventy W&W patients who were disease-free at the moment of recruitment were included. A minimum 2-year follow-up was considered. We graded late rectal toxicity according to the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer (RTOG/EORTC) scale and the Late Effects of Normal Tissue/Subjective Objective Management Analytic (LENT/SOMA) system. Long-term anorectal function was assessed with the Wexner score, the Low Anterior Resection Syndrome score (LARS score), and the Memorial Sloan Kettering Bowel Function Instrument (MSK BFI).

RESULTS

All patients received standard chemoradiotherapy consisting of a total dose of 5000 cGy in 25 fractions. The median tumor distance from the anal verge was 3 (IQR 2-4) cm. After a median follow-up of 43 (IQR 28-66) months, less than half of patients developed Grade 1 (40.0%) or Grade 2 (1.4%) late rectal toxicity, and no patients complained of higher grades. LENT/SOMA criteria also identified more patients with mild symptoms. The most frequent symptoms were sphincter control problems, mainly manifested as fecal urgency, reported by 60.0% of patients. For long-term anorectal function, the median LARS score was 16 (IQR 4-25). 17.1% of patients reported minor LARS and 15.7% reported major LARS. The median Wexner score was 2 (IQR 0-3). The median MSK BFI total score was 82 (IQR 77-86). Smoking history was an independent risk factor for anorectal dysfunction in multivariate analyses (OR = 6.491, 95% CI 1.536-27.432).

CONCLUSION

Rectal cancer patients managed by a watch-and-wait strategy after neoadjuvant chemoradiotherapy have retained satisfactory anorectal function. However, fecal urgency might be a common problem. Smoking history was an independent risk factor for long-term anorectal dysfunction. Prospective studies with emphasis on bowel function outcomes containing a larger number of patients are needed.

Biological Effective Dose (BED) in Evaluation of Rectal Dose in Prostate Cancer Patients with Hydrogel Spacer Who Underwent an EBRT with Different Fractionation Schemes

PURPOSE/OBJECTIVE(S)

To evaluate rectal dose sparing in prostate cancer patients with hydrogel spacer who underwent an external beam radiotherapy (EBRT) with different fractionation schemes.

MATERIALS/METHODS

In a previous study, we have reported that rectal sparing was achieved in prostate cancer patients with hydrogel spacer who underwent a combination therapy of EBRT and LDR brachytherapy (Zhang H, et al. J Appl Clin Med Phys, 2022). In this study, we focused on evaluation of spacer-related rectal sparing in patients who underwent an EBRT with conventional fractionation (81 Gy in 45 fractions), hypofractionation (70 Gy in 28 fractions), or stereotactic body radiotherapy (SBRT) for 40 Gy or 42.5 Gy in 5 fractions. In 172 patients, 119 patients were applied with injection of polyethylene-glycol hydrogel and others without the injection as control. In VMAT plans, doses to rectal wall were examined and converted to BED according to AAPM TG-137 (α/β ratio = 4 Gy).

RESULTS

On average, an interspace of 1cm between prostate and rectum was achieved by spacer insertion. Rectal wall was defined as 0.4cm thickness inside the outer contour of rectum, and the volume ranged from 4.5 cm3 to 21.3cm3 for patients with spacer and from 8.2cm3 to 35.1cm3 for those with no spacer. In conventional scheme, an average rectal BED was 120.0 Gy, 116.9 Gy, 114.0 Gy, 108.6 Gy, 87.6 Gy and 55.6 Gy to the volume of 0.1, 0.5, 1, 2, 5 and 10cm3, respectively, and BEDmean was 55.3 Gy in patients with no spacer. The BED decreased to 105.1 Gy, 96.3 Gy, 86.1 Gy, 75.4 Gy, 51.7 Gy and 26.9 Gy to the volume of 0.1, 0.5, 1, 2, 5 and 10cm3, respectively (p < 0.01), and BEDmean was 46.0 Gy in patients with spacer. In hypofractionation, rectal BED was in average of 115.8 Gy, 112.3 Gy, 109.8 Gy, 103 Gy, 81.6 and 52.8 Gy to the volume of 0.1, 0.5, 1, 2, 5 and 10cm3, respectively, and BEDmean was 48.6 Gy in patients with no spacer. Patients with spacer had significantly decreases of rectal BED, an average of 103 Gy, 91.7 Gy, 84.1 Gy, 72.8 Gy, 48.8 Gy and 26.0 Gy to the volume of 0.1, 0.5, 1, 2, 5 and 10cm3, respectively (p < 0.01), BEDmean was 42.4 Gy. In SBRT, average rectal BED in patients with spacer decreased to 93.6 Gy, 78.4 Gy, 69 Gy, 57.5 Gy, 38.5 Gy and 21.5 Gy, in comparison of 124.1 Gy, 117,4 Gy, 110.9 Gy, 97.3 Gy, 59.7 Gy and 32.3 Gy to the volume of 0.1, 0.5, 1, 2, 5 and 10cm3 in those without spacer, respectively (p <0.01). BEDmean decreased to 32.0 Gy in patient with spacer, compared with 43.2 Gy in those with no spacer.

CONCLUSION

Insertion of hydrogel spacer significantly improved rectal dose sparing, about 11.1% to 50.8% in conventional scheme, 12.4% to 51.6% in hypofractionation scheme, and 24.6% to 40.9% in SBRT patients. Furthermore, relatively more dose sparing on rectum was seen on the volume from 0.1cm3 to 2cm3 in SBRT patients.

A Machine Learning Method to Predict Pathological Complete Response of Esophageal Cancer after Neoadjuvant Chemoradiotherapy with Clinicohematological Markers and MR Radiomics: A Multi-Center Study

PURPOSE/OBJECTIVE(S)

Nearly 30% of patients with local advanced esophageal cancer achieved pathological complete response (pCR) after neoadjuvant chemoradiotherapy (nCRT), who may benefit from organ-preservation strategy under accurate prediction of pCR. We aimed to develop and validate machine learning models based on clinicohematological markers and MR radiomics to accurately predict pCR of esophageal cancer after nCRT.

MATERIALS/METHODS

In this multi-center study, eligible patients with esophageal cancer who received baseline MR scan (T2-weighted image) and nCRT plus surgery were enrolled between September 2014 and September 2022 at institution 1 (training set) and between December 2017 and August 2021 at institution 2 (testing set). Pre-nCRT and post-nCRT blood test results were collected to calculate hematological markers. Models were constructed by machine learning based on clinicohematological markers and MR radiomics to predict pCR. Area under the curve (AUC) and cut-off analysis were used to evaluate model performances.

RESULTS

Totally 154 patients (81 in the training set and 73 in the testing set) were enrolled. The combined model integrating pre-nCRT monocyte-to-lymphocyte ratio and 6 radiomics features achieved AUC of 0.800 (95% CI 0.671-0.918) in the testing set, with sensitivity of 79.2% (95% CI 62.5%-95.8%), specificity of 83.7% (95% CI 73.5%-93.9%), positive predictive value of 76.0% (95% CI 62.5%-90.0%), and negative predictive value of 89.6% (95% CI 82.0%-95.8%).

CONCLUSION

A machine learning model based on clinicohematological markers and MR radiomics to predict pCR after nCRT for patients with esophageal cancer was developed and validated, providing a novel tool for personalized treatment. It is necessary to further validate in more large datasets.

Hyperthermia Enhances the Radiosensitivity of Pancreatic Cancer Cells by Inhibiting Wnt2B Signaling

PURPOSE/OBJECTIVE(S)

Pancreatic cancer (PC) is a highly lethal human malignance. Due to unobvious symptoms at early stage, most of the patients with PC are diagnosed at late stages and lose the chance of surgical resection. Furthermore, PC patients are resistant to chemoradiotherapy and therefore show a dismal survival. Hyperthermia is commonly used as a sensitizer of chemotherapy or radiotherapy for the clinical treatment of human cancers. Our study aimed to investigate whether hyperthermia can improve the radiosensitivity of PC cells and uncover the involved mechanisms.

MATERIALS/METHODS

PC cells BxPC3, CFPAC-1 and PANC1 were heated to 43 ℃ 1 h before exposure to ionizing irradiation (IR). The radiosensitivity of PC cells were detected in vitro by colony formation assay, immunofluence analysis and western blotting. The mechanisms studies have been conducted using qRT-PCR analysis, cDNA/siRNA transfection and comet assay.

RESULTS

Hyperthermia significantly enhanced the radiosensitivity of PC cells by decreasing their colony formation and increasing DNA damage following IR. By qRT-PCR analysis of Wnt genes expressions, we found Wnt2B was significantly down-regulated in PC-3 cells which were treated with the combination of hyperthermia and IR compared with hyperthermia or IR alone. Functional assays showed that the expression level of Wnt2B was inversely associated with the radiosensitivity of PC-3 cells. Furthermore, we found hyperthermia inhibited the expression of DNA repair proteins such as p-BRCA1 and p-MRE11 in PC cells following IR CONCLUSION: Hyperthermia can significantly enhance the radiosensitivity of PC cells in a Wnt2B signaling-dependent manner.

The Effect of Dose-Fractionation Mode on the Immune Response and Therapeutic Effect of Lewis Lung Cancer Mice Model Based on Tumor Microenvironment

PURPOSE/OBJECTIVE(S)

The therapeutic effect of different groups of Lewis lung cancer mice and the expression of immune cells in peripheral blood and tumor tissues of mice were observed after different dose-segmentation modes of treatment, so as to select the most suitable for stimulating immune effect with good prognosis and small side effects.

MATERIALS/METHODS

Female homologous inbred C57BL/6 male mice at 6-8 weeks were selected and inoculated subcutaneously on the right thigh according to LLC: L929: lymphocyte = tumor cell suspension with PBMC(inactivated lymphocyte) = 5:1:1 ratio; after tumor growth to the size of 100-200mm3, different dose-segmentation modes were used for irradiation, which was divided into 5 groups, group A: no radiotherapy; Group B: 2Gy/qd, continuous radiotherapy for 30 days; Group C: 2Gy/bid, continuous radiotherapy for 13 days; Group D: 3Gy/bid, continuous radiotherapy for 10 days; Group E: 6Gy/qd, continuous radiotherapy for 8 days. On the 3rd day after radiotherapy, some mice were sacrificed, peripheral blood lymphocytes of mice were isolated with lymphocyte separation solution, and the transplanted tumor of mice was prepared into single-cell suspension. Then, the number of CD3+T cells, CD3+B cells, NK1.1 cells, CD3+CD4+T cells, CD3+CD8+T cells, CD4+Foxp3+Treg cells in peripheral blood and single-cell suspension of mice was detected by flow cytometry. HE staining was used to observe the tumor tissue structure of mice leg transplantation. The expressions of CD4, CD8, Foxp3 and CD31 in tumor tissues of each radiotherapy group were observed by immunohistochemical staining (IHC) in paraffin sections.

RESULTS

The survival time of mice in group C (2Gy/ bidx13d) was significantly improved compared with that in group B (2Gy/qdx30d), and the twin-daily segmentation mode could improve the elevation of Treg cells after once-daily segmentation mode radiotherapy in both peripheral blood and tumor tissues. There was no significant difference in the survival time of mice in group E (6Gy/qdx8d) and group D (3Gy/bidx10d), the number of Treg cells in peripheral blood of mice in group E was significantly lower than that in group D, but there were more Treg cells in tumor tissue of mice in group E than group D.

CONCLUSION

Compared with the control mice, the overall immunity of the experimental group was inhibited. The twice-daily segmentation mode in the conventional dose radiotherapy group significantly improved Treg in peripheral blood and tumor immune microenvironment and promoted neovascularization. The twice-daily segmentation mode in the high-dose radiotherapy group improved the immunosuppression of lymphocytes in peripheral blood but increased immunosuppression in tumor microenvironment.

Cost-Effectiveness of Short-Course Radiotherapy Based Total Neoadjuvant Therapy for Locally Advanced Rectal Cancer in China

PURPOSE/OBJECTIVE(S)

The phase III STELLAR (NCT02533271) trial demonstrated that four cycles of chemotherapy after short-course radiotherapy (SCRT-TNT) were not inferior to the standard care of long-course concurrent radiotherapy (LCRT) in patients with locally advanced rectal cancer (LARC). This study assessed the cost-effectiveness of SCRT-TNT versus LCRT in locally advanced rectal cancer in China on the basis of the STELLAR trial.

MATERIALS/METHODS

A Markov model was used to synthesize the healthcare costs and benefits of LARC patients based on results from the STELLAR trial. The model assumes that LARC who meet the inclusion criteria of the STELLAR trial experience four possible states: No Evidence of Disease (NED), locally recurrence, distant metastases, or any death from rectal cancer or other unrelated causes, where local recurrence continues to be classified as resectable and unresectable. The transition status period is 3 month, and 5 years is used to calculate direct medical costs and health benefits. The probabilities of states transition after SCRT-TNT or LCRT were derived from the results of the STELLAR trial and previous published article (Table.1). Costs were evaluated from the Chinese payer's perspective reported in early 2022 US dollars (US$1 = 6.78 Chinese Yuan). Sensitivity analyses were performed for key variables. Cost-effectiveness was evaluated using the incremental cost-effectiveness ratio and net monetary benefits. Effectiveness was defined as quality-adjusted life-years (QALYs). Willingness-to-pay (WTP) threshold was set at $43500/QALY. Data were collected from October 3, 2020, to September 20, 2021, and analyzed from November 15, 2020, to October 25, 2021.

RESULTS

During the 5-year horizon, for the base case scenario, SCRT-TNT incurred a lower total cost and higher QALYs compared with LCCRT. The total cost was $65767 and QALYs were 1.77 for SCRT-TNT; for LCCRT, the total cost was $72802 and QALYs were 1.64. This resulted in an ICER of -$ 55470.69 per QALY. Therefore, SCRT-TNT was a cost-saving and dominating treatment strategy compared with LCRT. Sensitivity analysis showed that ICERs were most sensitive to the parameters of distant metastases risk after treatment.

CONCLUSION

SCRT-TNT in locally advanced rectal cancer can be a cost-effective alternative to LCRT in China, and should be considered in appropriately selected patients.

Radiotherapy Combined with PD-L1 Antibody Exerts a Synergistic Anti-tumor Effect in a Mouse Model of Esophageal Squamous Cell Carcinoma

PURPOSE/OBJECTIVE(S)

The combination of radiotherapy and immune checkpoint inhibitors (ICIs) has been shown to exert synergistic anti-tumor effects in various tumors. In esophageal squamous cell carcinoma (ESCC), several clinical trials of radiotherapy combined with ICIs are undergoing or have been finished. However, the efficacy and action mechanisms of radiotherapy combined with ICIs is still not clear in ESCC. Our study aimed to investigate whether radiotherapy improved the anti-cancer effect of PD-L1 antibody and the effect of this combination therapy on tumor-immune microenvironment.

MATERIALS/METHODS

The mouse esophageal cancer cell line mEC25 was implanted into the armpits of female C57 mice. When the tumor volume grew to 150-250 mm3, the mice were randomly divided into different groups including control group (administration of IgG antibody), radiotherapy group (12 Gy at 4 Gy per fraction), PD-L1 antibody group (200 mg/kg i.p. for three times) and combination group (fractionated radiation combined with PD-L1 antibody was delivered on day 1, day 4 and day 7, the day when fractionated radiation began was recorded as day 1).The mice were sacrificed on the 1st, 3rd and 7th day after the treatment was ended. The tumor, spleen and draining lymph nodes of the mice were collected and analyzed using flow cytometry (FCM), and the tumor volume and survival time of mice were calculated.

RESULTS

Compared with radiotherapy or PD-L1 antibody alone, the combination therapy significantly prolonged the survival time of mice and decreased the growth rate of xenograft tumors FCM analysis showed that the combination therapy significantly increased the infiltration and cytotoxicity of effector T cells and reduced the proportion of M2 macrophages in tumor, spleen and lymph nodes. In addition, in tumor and spleen, the proportion of regulatory T cells (Tregs) decreased in the group of combination therapy. In tumor, spleen, and lymph nodes, the proportion of central memory T cell (TCM) was increased in the group of combination therapy.

CONCLUSION

The anti-tumor effect of radiotherapy combined with PD-L1 antibody is superior to single treatment in the mouse model of esophageal cancer. Radiotherapy can shape tumor-immune microenvironment, allowing the infiltration of effector T cells and exclusion of immune-suppressive cells such as M2 macrophages and Tregs.

CDC73 Impairment of MAPK1 Ubiquitination and Activation of the mTOR Signaling Pathway

PURPOSE/OBJECTIVE(S)

CDC73 has been reported to be upregulated in breast cancer. This study aimed to illuminate the underlying mechanism by which CDC73 mediates breast cancer.

MATERIALS/METHODS

Here, a breast cancer tissue microarray and three breast cancer cell lines MDA-MB-231, BT-549 as well as MCF-7 were employed. Using RNAi method, we knocked down CDC73 and MAPK1 in breast cancer cells. CDC73 overexpression plasmids (LV-013) were generated through pMD2.G and pSPAX2 vectors. Cell events related to tumor development were analyzed through Celigo cell counting assay, a cell counting kit, wound healing assay, Transwell assay and flow cytometry analysis. The exploration on the underlying mechanism was based on PrimeView human gene expression array. Xenograft tumor models were constructed to visualize the effects of CDC73/MAPK2 on breast cancer progression.

RESULTS

CDC73 was abundantly expressed in breast cancer tissues and cell lines, and the expression of CDC73 was related to poor prognosis of patients. In breast cancer, CDC73 could promote the proliferation and migration of tumor cells, while disrupting apoptosis. Also, we found that CBL, an E3 ubiquitin ligase, could interact with CDC73 and promote MAPK1 ubiquitination and degradation of this protein. In addition, silencing MAPK1 led to a suppression of breast cancer cell growth in vitro and in vivo, and even abolished the promoting effects of CDC73 overexpression. We also found that mTOR pathway played a role in CDC73-mediated breast cancer. mTOR pathway inhibitor reversed cell phenotypes induced by CDC73 overexpression.

CONCLUSION

CDC73 promoted MAPK1 ubiquitination and degradation so that affected MAPK1 level and subsequently led to breast cancer progression, providing a novel therapeutic strategy to combat cancer.

Global burden of neoplasms attributable to specific occupational carcinogens over 30 years: a population-based study

OBJECTIVES

The study aimed to analyze the global burden of occupational neoplasms from various epidemiological perspectives.

STUDY DESIGN

In this cross-sectional study, secondary analyses were conducted to assess the burden of neoplasms attributable to occupational carcinogens and their distribution characteristics using data from GBD 2019 and the World Bank database.

METHODS

Based on the GBD 2019 and the World Bank database, we analyzed the global burden of occupational neoplasms including the age-period-cohort model, decomposition analysis, health inequality analysis, and panel model. All analyses were conducted in R (version 4.0.3) and Joinpoint (version 4.9.1).

RESULTS

The absolute number of neoplasms burden attributable to occupational carcinogens has continued to rise over 30 years. In 2019, occupational neoplasms caused 333,867 [95% uncertainty interval (UI): 263,491 to 404,641] mortalities and 6,964,775 (95% UI: 5,467,884 to 8,580,431) disability-adjusted life years (DALYs) globally. Greenland, Monaco, the Netherlands, and Andorra suffered the highest burden. The burden was higher in countries with a higher sociodemographic index. The age effect was prominent in the elderly, and the 1925 birth cohort had the highest cohort effect. Population growth was the most significant driver of the mortalities (89%) and DALYs (111%) change. Moreover, the proportion of urban population was significantly positively associated with the disease burden, while GDP per capita was negatively correlated with the disease burden.

CONCLUSIONS

The burden of occupational neoplasms was unevenly distributed across locations and populations. The need for rational allocation of healthcare resources was urgent.

Locoregional radiotherapy improves survival outcomes in de novo metastatic nasopharyngeal carcinoma treated with chemoimmunotherapy

BACKGROUND

We aimed to investigate the efficacy of locoregional radiotherapy (LRRT) in patients with de novo metastatic nasopharyngeal carcinoma (dmNPC) receiving chemotherapy combined with anti-programmed cell death receptor-1 monoclonal antibodies (anti-PD-1 mAbs) as first-line treatment and identify optimal candidates for LRRT.

MATERIALS AND METHODS

We enrolled patients with dmNPC receiving platinum-based palliative chemotherapy and anti-PD-1 mAbs followed or not followed by LRRT from four centers. The endpoints were progression-free survival (PFS), objective response rate (ORR), and overall survival (OS). We used the inverse probability of treatment weighting (IPTW) to balance the baseline characteristics of the LRRT and non-LRRT groups to minimize selection bias before comparative analyses. Multivariate analyses were carried out using the Cox proportional hazards model.

RESULTS

We included 163 patients with dmNPC (median follow-up: 22 months). The median PFS was 20 months, and the ORR was 92.0%; the median OS was not achieved. After IPTW adjustments, patients who received LRRT had a significant survival benefit over those not receiving LRRT (median PFS: 28 versus 15 months, P < 0.001). The Epstein-Barr virus DNA (EBV DNA) level after four to six cycles of anti-PD-1 mAbs [weighted hazard ratio (HR): 2.19, 95% confidence interval (CI) 1.22-3.92, P = 0.008] and LRRT (weighted HR: 0.58, 95% CI 0.34-0.99, P = 0.04) were independent prognostic factors. Patients with undetectable EBV DNA levels after four to six cycles of anti-PD-1 mAbs (early EBV DNA clearance) benefitted from LRRT (HR: 0.41, 95% CI 0.22-0.79, P = 0.008), whereas those with detectable levels did not (HR: 1.30, 95% CI 0.59-2.87, P = 0.51).

CONCLUSIONS

Palliative chemotherapy combined with anti-PD-1 mAbs followed by LRRT was associated with improved PFS in patients with dmNPC, especially for patients with early EBV DNA clearance.

[A clinical cohort study of split and whole liver transplantations]

Objective: To investigate the surgical efficacy of split liver transplantation. Methods: Patients who underwent liver transplantation at the Affiliated Hospital of Qingdao University between January 2015 and December 2022 were retrospectively analyzed. They were divided into split liver transplantation group (n=60) and whole liver transplantation group (n=765)according to graft types.In the split liver transplantation group, there were 23 males and 37 females, aged (52.5±10.2) years, and the body mass index was (22.4±3.3) kg/m2. In the whole liver transplantation group, there were 630 males and 135 females, aged (51.2±9.6) years, and body mass index was (24.5±3.7) kg/m2.The basic data of the two groups were matched 1∶1 using the propensity score matching method. The independent sample t test and χ2 test were used to compare the intraoperative and postoperative recovery of the two groups of donors and recipients. The overall survival rate and the graft survival rate of the two groups were analyzed by Kaplan-Meier method and the cumulative survival rate was compared by the Log-rank test. Results: Fifty-one well-matched pairs of data with similar baseline characteristics were obtained. The ratio of graft mass to recipient body weight in the matched split liver transplantation group was (1.78±0.55)%. Operation time(M(IQR))(10.8(1.5)hours vs. 8.0(1.9)hours,U=6.608,P<0.01) and cold ischaemia time(5.4(1.3)hours vs. 4.6(2.2)hours,U=2.825,P=0.005) were significantly longer in the split liver transplantation group than those in the whole liver transplantation group. Intra-operative anhepatic phase(53.0(15.0)minutes vs. 57.0(24.0)minutes,U=1.048,P=0.295),bleeding volume(1 000(1 400)ml vs. 1 200(1 200)ml,U=0.966,P=0.334) and intraoperative instillation of red blood cells(9.0(6.5)U vs. 11.0(11.0)U,U=1.732,P=0.083) were not significantly different between the two groups. However,the split liver transplantation group showed significantly longer postoperative intensive care unit stay(5.0(3.0)days vs. 4.0(4.0)days,U=2.677,P=0.007) and postoperative hospital stay(30.0(15.0)days vs. 26.0(15.0)days,U=2.237,P=0.025) and significantly higher incidence of postoperative complications(56.8%(29/51) vs. 36.6%(19/51),χ2=3.935,P=0.047) than the whole liver transplantation group. Furthermore,levels of alanine transaminase and aspartate aminotransferase were significantly higher on postoperative days 1,4 and 7 in the split liver transplantation group(all P<0.05) than in the whole liver transplantation group;however,there were no significant differences in these levels on postoperative days 14 and 28. The time to restoration of normal liver function in both groups(12.5(13.7)days vs. 9.0(12.5)days,U=1.607,P=0.108) was not statistically significant. Furthermore,the median follow-up time after surgery was 25.6 months in both groups. In postoperative years 1,2,3 and 5, the graft survival rates were 88.1%,80.8%,77.8% and 66.7% in the whole liver transplantation group and 80.3%,70.3%,67.3% and 60.5% in the split liver transplantation group(P=0.171),respectively. The patient survival rates in post-operative years 1,2,3 and 5 were 88.1%,80.8%,77.8% and 66.7% in the whole liver transplantation group and 80.3%,75.9%,70.3% and 63.3% in the split liver transplantation group,respectively(P=0.252). However,the differences of graft survival rates and patient survival rates between the two groups were not significant. Conclusion: Although it affects the early recovery of patients after liver transplantation,split liver transplantation has no effect on long-term survival rates and demonstrates surgical efficacy similar to that of whole liver transplantation.

The Role of Esophagography in the Diagnosis of Orthotopic Esophageal Squamous Cell Carcinoma in a Mouse Mode

PURPOSE/OBJECTIVE(S)

Animal models play an irreplaceable role in pre-clinical studies of various tumors, mainly including xenogeneic/homograft subcutaneous tumor models. However, the subcutaneous transplanted tumor model is separated from the microenvironment of the primary tissue and fail to accurately simulate the growth of tumor cells in vivo. Therefore, orthotopic tumor models play an increasingly important role. For esophageal squamous cell carcinoma, chemotherapy-induced methods have successfully established mouse models of esophageal squamous cell carcinoma, but past experiments have found that it is still a challenge to confirm the success of the mouse model of esophageal cancer. The pathological diagnosis of the esophageal cancer tissue obtained from the killed mouse model remains the gold standard, but it also represents a lost opportunity to evaluate the efficacy of subsequent treatment. Notedly, esophagography is the primary examination for clinical patients with esophageal cancer. Therefore, the aim of this study is to evaluate whether esophagography can be used to establish a successful in situ mouse model of esophageal cancer.

MATERIALS/METHODS

Referring to previous literature, we used the chemical drug 4-Nitroquinoline N-oxide (4-NQO) to induce orthotopic tumor model: A certain amount of 4-NQO was dissolved in propylene glycol to make a 2% stock solution, and then dissolved in 200ml of sterile water for the daily drinking water of mice. The water was kept in the dark and replaced once a week. After 16 weeks of induction, the drinking water was replaced by the same volume of sterile water and continued to be fed for 12 weeks. The mice were subsequently subjected to esophagography: First, the mice were fixed on a plastic plate, and the gavage needle was slowly inserted into the stomach, then slowly withdrawn out and gradually injected with meglumine diphosphate, with a total amount of 0.1-0.2ml. Then the radiolucent film was taken immediately, and three positions were selected, including the plain film, the standing film and the lateral film. After that, the mice were sacrificed and the esophagus of the mice was isolated and embedded in sections for pathological and immunohistochemical diagnosis. Finally, the results were compared with the imaging results.

RESULTS

Based on the comparison of imaging and pathological results, we found that most of the esophageal segments with filling defects on esophagography were pathologically diagnosed as esophageal squamous cell carcinoma, and another part were diagnosed as esophageal papilloma. Compared with CT and MRI, esophagography has the advantages of simple operation and less consumable materials.

CONCLUSION

We found that esophagography is a new non-invasive auxiliary diagnostic method for the successful establishment of an orthotopic mouse model of esophageal squamous cell carcinoma.

Refining the TNM M1 Subcategory for De Novo Metastatic Nasopharyngeal Carcinoma

PURPOSE/OBJECTIVE(S)

To refine oligometastatic disease (OMD) and construct M1 categories for de novo metastatic nasopharyngeal carcinoma (dmNPC) MATERIALS/METHODS: We included 504 patients who received chemotherapy and/or radiotherapy between 2010-2019 from two centers (training and validation cohort). Multivariable analyses were used to evaluate the prognostic value of OMD and metastatic organs, which were then used to construct M1 categories RESULTS: The median follow-up for the training and validation cohorts were 46 and 57 months, respectively. OMD (≤ 2 metastatic organs and ≤ 5 metastatic lesions) had the highest C-index compared to the other models in both cohorts. Multivariable analyses, in which both OMD and liver metastases did not coexist, revealed that OMD (hazard ratio [HR] = 2.110 and 1.598) and liver metastases (HR = 1.572 and 1.452) were prognostic factors for overall survival (OS) in both cohorts. Based on OMD and liver metastases, patients with dmNPC were divided into M1a (OMD without liver metastases) and M1b (OMD with liver metastases or polymetastatic disease). The 3-year OS of the M1a patients was better than that of the M1b patients in both cohorts (both p < 0.001). In the anti-PD1 mAb and chemotherapy cohorts, patients with M1ahad a significantly better median progression-free survival than those with M1b (p < 0.001) CONCLUSION: OMD with ≤ 2 metastatic organs and ≤ 5 metastatic lesions is an appropriate definition for dmNPC. M1 subcategories constructed based on OMD and liver metastases improved prognostic evaluation for patients with dmNPC who received chemotherapy or antiPD1 mAb treatment.

[Molecular detection and phylogenetic analysis of Wolbachia infection in common mosquito species in Henan Province]

OBJECTIVE

To investigate the infection and genotypes of Wolbachia in common mosquito species in Henan Province, so as to provide insights into management of mosquito-borne diseases.

METHODS

Aedes, Culex and Anopheles samples were collected from cowsheds, sheepfolds and human houses in Puyang, Nanyang City and Xuchang cities of Henan Province from July to September, 2022, and the infection of Wolbachia was detected. The 16S rDNA and wsp genes of Wolbachia were amplified and sequenced. Sequence alignment was performed using the BLAST software, and the obtained 16S rDNA gene sequence was compared with the sequence of the 16S rDNA gene in GenBank database. In addition, the phylogenetic trees were created based on 16S rDNA and wsp gene sequences using the software MEGA 11.0.

RESULTS

A total 506 female adult mosquitoes were collected from three sampling sites in Nanyang, Xuchang City and Puyang cities from July to September, 2022. The overall detection of Wolbachia was 45.1% (228/506) in mosquitoes, with a higher detection rate in A. albopictus than in Cx. pipiens pallens [97.9% (143/146) vs. 50.6% (85/168); χ2 = 88.064, P < 0.01]. The detection of Wolbachia in Cx. pipiens pallens was higher in Xuchang City (96.8%, 62/64) than in Nanyang (15.6%, 7/45) and Puyang cities (27.1%, 16/59) (χ2 = 89.950, P < 0.01). The homologies of obtained Wolbachia 16S rDNA and wsp gene sequences were 95.3% to 100.0% and 81.7% to 99.8%. Phylogenetic analysis based on wsp gene sequences showed Wolbachia supergroups A and B in mosquito samples, with wAlbA and wMors strains in supergroup A and wPip and wAlbB strains in supergroup B. Wolbachia strain wAlbB infection was detected in A. albopictus in Puyang and Nanyang Cities, while Wolbachia strain wPip infection was identified in A. albopictus in Xuchang City. Wolbachia strain wAlbA infection was detected in Cx. pipiens pallens sampled from three cities, and one Cx. pipiens pallens was found to be infected with Wolbachia strain wMors in Nanyang City.

CONCLUSIONS

Wolbachia infection is commonly prevalent in Ae. albopictus and Cx. pipiens pallens from Henan Province, and Wolbachia strains wAlbB and wAlbA are predominant in Ae. albopictus, while wPip strain is predominant in Cx. pipiens pallens. This is the first report to present Wolbachia wMors strain infection in Cx. pipiens pallens in Henan Province.

[Value of postoperative radiotherapy and analysis of prognostic factors in early-stage neuroendocrine carcinoma of cervix]

Objective: To evaluate the effect of postoperative radiotherapy and high-risk pathological factors on the prognosis of early-stage neuroendocrine carcinoma of cervix (NECC). Methods: A single-center retrospective cohort study of early-stage NECC in Peking Union Medical College Hospital from January 2011 to April 2022 were enrolled. The patients were treated with radical hysterectomy±adjuvant treatment. They were divided into postoperative non-radiation group and postoperative radiation group. The possible postoperative recurrence risk factors identified by univariate analysis were assessed using multivariate logistic regression. The Kaplan-Meier method was used to analyze the progression free survival (PFS), overall survival (OS), recurrence rate, and mortality rate. Results: (1) Sixty-two cases were included in the study, including 33 cases in postoperative non-radiation group and 29 cases in postoperative radiation group. (2) The median follow-up time was 37 months (ranged 12-116 months), with 23 cases (37%) experienced recurrences. There were 7 cases (11%) pelvic recurrences and 20 cases (32%) distant recurrences, in which including 4 cases (6%) both pelvic and distant recurrences. Compared with postoperative non-radiation group, the postoperative radiation group had a lower pelvic recurrence rate (18% vs 3%; P=0.074) but without statistic difference, a slightly elevated distant recurrence rate (24% vs 41%; P=0.150) and overall recurrence rate (33% vs 41%; P=0.513) without statistically significances. Univariate analysis showed that lymph-vascular space invasion and the depth of cervical stromal invasion≥1/2 were risk factors for postoperative recurrence (all P<0.05). Multivariate analysis showed lymph-vascular space invasion was an independent predictor for postoperative recurrence (OR=23.03, 95%CI: 3.55-149.39, P=0.001). (3) During the follow-up period, 18 cases (29%, 18/62) died with tumor, with 10 cases (30%, 10/33) in postoperative non-radiation group and 8 cases (28%, 8/29) in postoperative radiation group, without significant difference (P=0.814). The postoperative 3-year and 5-year survival rate was 79.2%, 60.8%. The depth of cervical stromal invasion≥1/2 was more common in postoperative radiation group (27% vs 64%; P=0.011), and postoperative radiation in such patients showed an extended trend in PFS (32.3 vs 53.9 months) and OS (39.4 vs 73.4 months) but without statistic differences (P=0.704, P=0.371). Compared with postoperative non-radiation group, the postoperative radiation did not improve PFS (54.5 vs 37.3 months; P=0.860) and OS (56.2 vs 62.4 months; P=0.550) in patients with lymph-vascular space invasion. Conclusions: Postoperative radiation in early-stage NECC patients has a trend to reduce pelvic recurrence but not appear to decrease distant recurrence and overall recurrence, and has not improved mortality. For patients with the depth of cervical stromal invasion≥1/2, postoperative radiation has a trend of prolonging OS and PFS but without statistic difference. Lymph-vascular space invasion is an independent predictor for postoperative recurrence, but postoperative radiation in such patients does not seem to have any survival benefits.

Search for Λ[over ¯]-Λ Baryon-Number-Violating Oscillations in the Decay J/ψ→pK^{-}Λ[over ¯]+c.c

We report on the first search for Λ[over ¯]-Λ oscillations in the decay J/ψ→pK^{-}Λ[over ¯]+c.c. by analyzing 1.31×10^{9}  J/ψ events accumulated with the BESIII detector at the BEPCII collider. The J/ψ events are produced using e^{+}e^{-} collisions at a center of mass energy sqrt[s]=3.097  GeV. No evidence for hyperon oscillations is observed. The upper limit for the oscillation rate of Λ[over ¯] to Λ hyperons is determined to be P(Λ)=[B(J/ψ→pK^{-}Λ+c.c.)/B(J/ψ→pK^{-}Λ[over ¯]+c.c.)]<4.4×10^{-6} corresponding to an oscillation parameter δm_{ΛΛ[over ¯]} of less than 3.8×10^{-18}  GeV at the 90% confidence level.

Measurement of the Dependence of the Hadron Production Fraction Ratios f_{s}/f_{u} and f_{d}/f_{u} on B Meson Kinematic Variables in Proton-Proton Collisions at sqrt[s]=13 TeV

The dependence of the ratio between the B_{s}^{0} and B^{+} hadron production fractions, f_{s}/f_{u}, on the transverse momentum (p_{T}) and rapidity of the B mesons is studied using the decay channels B_{s}^{0}→J/ψϕ and B^{+}→J/ψK^{+}. The analysis uses a data sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the CMS experiment in 2018 and corresponding to an integrated luminosity of 61.6  fb^{-1}. The f_{s}/f_{u} ratio is observed to depend on the B p_{T} and to be consistent with becoming asymptotically constant at large p_{T}. No rapidity dependence is observed. The ratio of the B^{0} to B^{+} meson production fractions, f_{d}/f_{u}, is also measured, for the first time in proton-proton collisions, using the B^{0}→J/ψK^{*0} decay channel. The result is found to be within 1 standard deviation of unity and independent of p_{T} and rapidity, as expected from isospin invariance.

[Clinical and genotypic analysis of hereditary spherocytosis combined with cholestasis among pediatric patients]

Objective: To understand the clinical and genetic characteristics of hereditary spherocytosis (HS) combined with cholestasis among pediatric patients. Methods: 12 cases of HS children accompanied by cholestasis at Hunan Children's Hospital were selected as the research subjects between January 2013 and December 2022. Clinical data were collected. Whole-exome sequencing was performed by second-generation sequencing. Suspected pathogenic mutation sites were verified by Sanger sequencing. Results: All pediatric patients were admitted to the hospital due to their yellow skin tone. Eight cases (66.67%) had a positive family history. The clinical manifestations were jaundice, splenomegaly (12/12), abdominal pain, anemia (4/12), and hepatomegaly (5/12). All pediatric patients had decreased hemoglobin, an increased reticulocyte ratio, total bilirubin and direct bilirubin, a positive erythrocyte fragility test, and remarkable spherical erythrocytes in their peripheral blood. Seven cases had elevated aminotransferase; four cases had severely elevated aminotransferase and bilirubin; eight cases had biliary calculi; and two cases had a dilated biliary tract. Liver pathological examination showed mild damage to the liver cells (G1S1) in three pediatric cases. Five children had a total of six unreported mutations: SPTB gene c.2431_2450del, c.4974-2A > G, c.2575G > A, and exon 22-35 deletion; ANK1 gene: c.2379-2380delC; and c .6dupC. Children still had abnormal bilirubin levels following treatment. Two pediatric cases underwent splenectomy. Bilirubin and hemoglobin levels returned to normal after surgery. Conclusion: Children with HS may experience cholestasis, and those with poor treatment results may consider undergoing a splenectomy. Six new types of variants have expanded the HS gene mutation spectrum.