Yuan Fei Li

Immunotherapy has improved outcomes for patients with esophageal squamous cell carcinoma (ESCC), yet a substantial proportion develop resistance. The tumor microenvironment (TME) drives this resistance through four hallmarks: physical barriers formed by cancer-associated fibroblast (CAF)-deposited extracellular matrix (ECM) and elevated interstitial fluid pressure (IFP), enrichment of immunosuppressive cells, effector T cell exhaustion, and impaired antigen presentation. Radiotherapy, a cornerstone of ESCC treatment, has the potential to simultaneously target these barriers through multiple complementary mechanisms. Preclinical evidence suggests that high-dose or ablative radiotherapy can drive CAFs into irreversible senescence, triggering a senescence-associated secretory phenotype (SASP) that upregulates matrix metalloproteinases (MMPs) and degrades ECM. In preclinical models, IFP can be reduced through vascular normalization (low-dose) or tumor debulking (high-dose). There is also evidence, largely from experimental systems, that radiotherapy may eliminate immunosuppressive cells, ameliorate T cell exhaustion, and upregulate MHC class I and PD-L1 expression to restore immune recognition. These immunomodulatory effects appear to be dose- and fractionation-dependent; conventional fractionation often falls below the threshold required to dismantle the physical barrier—a factor that is hypothesized to contribute to, but does not fully account for, the limited success of chemo-immuno-radiotherapy trials to date. Building on this mechanistic framework, we evaluate clinical evidence for radiotherapy-immunotherapy combinations in ICI-resistant ESCC, compare the distinct roles of stereotactic body radiotherapy (SBRT) and low-dose radiotherapy (LDRT), and propose a “barrier-exhaustion score” as a hypothetical tool to guide individualized treatment. This review provides a mechanistic rationale and clinical perspective for radiotherapy-based strategies to overcome immunotherapy resistance in ESCC.

Type 2 diabetes increases the risk various types of cancer and is associated with a poor prognosis therein. There is also evidence that the disease is associated with cancer metastasis. Centrosome amplification can initiate tumorigenesis with metastasis in vivo and increase the invasiveness of cancer cells in vitro. Our previous study reported that type 2 diabetes promotes centrosome amplification via the upregulation and centrosomal translocation of Rho‑associated protein kinase 1 (ROCK1), which suggests that centrosome amplification is a candidate biological link between type 2 diabetes and cancer development. In the present study, functional proteomics analysis was used to further investigate the molecular pathways underlying centrosome amplification by targeting ROCK1 binding partners. High glucose, insulin and palmitic acid were used to induce centrosome amplification, and immunofluorescent staining was employed to visualize centrosomal alterations. Combined with immunoprecipitation, mass spectrometry‑based proteomics analysis was used to identify ROCK1 binding proteins, and protein complex disruption was achieved by siRNA‑knockdown. In total, 1,148 ROCK1 binding proteins were identified, among which 106 proteins were exclusively associated with the treated samples, 193 were only associated with the control samples, and 849 were found in both the control and treated samples. Of the proteins with evidence of centrosomal localization, Dynactin subunit 2 (DCTN2) was confirmed to be localized to the centrosomes. Treating the cells with high glucose, insulin and palmitic acid increased the protein levels of ROCK1 and DCTN2, promoted their binding with each other, and triggered centrosome amplification. Disruption of the protein complex by knocking down ROCK1 or DCTN2 expression partially attenuated centrosome amplification, while simultaneous knockdown of both proteins completely inhibited centrosome amplification. These results suggested ROCK1‑DCTN2 binding as a signal for the regulation of centrosome homeostasis, which is key for diabetes‑associated centrosome amplification, and enriches our knowledge of centrosome biology. Therefore, the ROCK1‑DCTN2 complex may serve as a target for inhibiting centrosome amplification both in research or future therapeutic development.

Rationale: Cachexia is a clinically relevant syndrome in cancer that is associated with reduced tolerance to anticancer therapy, reduced quality of life, and reduced survival rates. Cachexia is most prevalent in pancreatic, gastric, colorectal, lung, and head and neck cancers. It is rarely documented in breast cancer patients. Patient concerns: In our case report of a breast cancer patient with bone metastasis who was monitored throughout the course of her treatment, we document the development of cachexia using image analyses in relation to her metastatic burden. In the 2-year period, from April 10, 2015, to February 09, 2017, she lost 16% of her baseline weight. During this time, she was repeatedly hospitalized for chest tightness, edema of both lower limbs, numbness and pain in the left lower extremity and backache. Diagnoses: Our patient was a 46-year-old premenopausal woman when she was firstly diagnosed. Several years after surgery for invasive ductal carcinoma of the left breast, she had multiple systemic bone metastases (the thoracic spine, the ribs, etc), lung metastasis, bilateral axillary lymph node metastasis, and metastasis of the right neck lymph node in IV area. Interventions: The patient completed 6 cycles of postoperative adjuvant chemotherapy and long-term endocrine therapy after a radical mastectomy for breast cancer. During the fourth progression, 6 cycles of rescue chemotherapy were performed. Local lumbosacral radiotherapy, and lumbar surgery were carried out to relieve symptoms after several progressions. Outcomes: She became extremely thin, weighing only 50 kg at admission on July 23, 2018. This eventually led to multiple organ failure and death. Lessons: We noted a strong negative correlation between the abdominal muscle area and the metastatic tumor area at the second lumbar vertebral (L2) level. The monitoring of abdominal muscle wasting may serve as a marker, and therefore a prognostic factor, for both cachexia and the extent of metastatic disease. This is especially true with breast cancer, where metastasis to bone is frequent. Our data from a computational tomography radiological quantification, may provide clinicians with early indications of the extent of cachexia in metastatic breast cancer patients.

It has been reported recently that type 2 diabetes promotes centrosome amplification via 14‐3‐3σ/ROCK1 complex. In the present study, 14‐3‐3σ interacting proteins are characterized and their roles in the centrosome amplification by high glucose, insulin, and palmitic acid are investigated. Co‐immunoprecipitation in combination with MS analysis identified 134 proteins that interact with 14‐3‐3σ, which include heat shock 70 kDa protein 4 (Hsp74). Gene ontology analyses reveal that many of them are enriched in binding activity. Kyoto Encyclopedia of Genes and Genomes analysis shows that the top three enriched pathways are ribosome, carbon metabolism, and biosynthesis of amino acids. Molecular and functional investigations show that the high glucose, insulin, and palmitic acid increase the expression and binding of 14‐3‐3σ and Hsp74 as well as centrosome amplification, all of which are inhibited by knockdown of 14‐3‐3σ or Hsp74. Moreover, molecular docking analysis shows that the interaction between the 14‐3‐3σ and the Hsp74 is mainly through hydrophobic contacts and a lesser degree ionic interactions and hydrogen bond by different amino acids residues. In conclusion, the results suggest that the experimental treatment triggers centrosome amplification via upregulations of expression and binding of 14‐3‐3σ and Hsp74.

Type2 diabetes is associated with oxidative stress which can cause cell centrosome amplification. The study investigated centrosome amplification in type 2 diabetes and the underlying mechanisms. We found that centrosome amplification was increased in the peripheral blood mononuclear cells (PBMC) from the type 2 diabetic patients, which correlated with the levels of fasting blood glucose and HbA1c. High glucose, insulin and palmitic acid, alone or in combinations, induced ROS production and centrosome amplification. Together, they increased AKT activation as well as the expression, binding and centrosome translation of ROCK1 and 14-3-3σ. Results from further analyses showed that AKT-ROS-dependent upregulations of expression, binding and centrosome translocation of ROCK1 and 14-3-3σ was the molecular pathway underlying the centrosome amplification induced by high glucose, insulin and palmitic acid. Moreover, the increases in AKT activation and ROS production as well as expression, binding and centrosome distribution of ROCK1 and 14-3-3σ were confirmed in the PBMC from the patients with type 2 diabetes. In conclusion, our results show that type 2 diabetes promotes cell centrosome amplification, and suggest that the diabetic pathophysiological factors-activated AKT-ROS-dependent signalling of ROCK1 and 14-3-3σ is the underlying molecular mechanism.

Dental pulp stem cells (DPSCs) can be driven into odontoblast, osteoblast, and chondrocyte lineages in different inductive media. However, the differentiation potential of naive DPSCs after serial passaging in the routine culture system has not been fully elucidated. DPSCs were isolated from human/rat dental pulps by the magnetic activated cell sorting based on STRO-1 expression, cultured and passaged in the conventional culture media. The biological features of STRO-1⁺ DPSCs at the 1^st and 9^th passages were investigated. During the long-term passage, the proliferation ability of human STRO-1⁺ DPSCs was downregulated as indicated by the growth kinetics. When compared with STRO-1⁺ DPSCs at the 1^st passage (DPSC-P1), the expression of mature osteoblast-specific genes/proteins (alkaline phosphatase, bone sialoprotein, osterix, and osteopontin), odontoblast-specific gene/protein (dentin sialophosphoprotein and dentin sialoprotein), and chondrocyte-specific gene/protein (type II collagen) was significantly upregulated in human STRO-1⁺ DPSCs at the 9^th passage (DPSC-P9). Furthermore, human DPSC-P9 cells in the mineralization-inducing media presented higher levels of alkaline phosphatase at day 3 and day 7 respectively, and produced more mineralized matrix than DPSC-P9 cells at day 14. In vivo transplantation results showed that rat DPSC-P1 cell pellets developed into dentin, bone and cartilage structures respectively, while DPSC-P9 cells can only generate bone tissues. These findings suggest that STRO-1⁺ DPSCs consist of several interrelated subpopulations which can spontaneously differentiate into odontoblasts, osteoblasts, and chondrocytes. The differentiation capacity of these DPSCs changes during cell passaging, and DPSCs at the 9^th passage restrict their differentiation potential to the osteoblast lineage in vivo.