Impact of Pretreatment Total Cholesterol Level Is Associated With Metastasis of Prostate Cancer

Cholesterol metabolism in tumor microenvironment: cancer hallmarks and therapeutic opportunities

Cholesterol is crucial for cell survival and growth, and dysregulation of cholesterol homeostasis has been linked to the development of cancer. The tumor microenvironment (TME) facilitates tumor cell survival and growth, and crosstalk between cholesterol metabolism and the TME contributes to tumorigenesis and tumor progression. Targeting cholesterol metabolism has demonstrated significant antitumor effects in preclinical and clinical studies. In this review, we discuss the regulatory mechanisms of cholesterol homeostasis and the impact of its dysregulation on the hallmarks of cancer. We also describe how cholesterol metabolism reprograms the TME across seven specialized microenvironments. Furthermore, we discuss the potential of targeting cholesterol metabolism as a therapeutic strategy for tumors. This approach not only exerts antitumor effects in monotherapy and combination therapy but also mitigates the adverse effects associated with conventional tumor therapy. Finally, we outline the unresolved questions and suggest potential avenues for future investigations on cholesterol metabolism in relation to cancer.

Prognostic value of preoperative immune-nutritional scoring systems in remnant gastric cancer patients undergoing surgery

BACKGROUND

Remnant gastric cancer (GC) is defined as GC that occurs five years or more after gastrectomy. Systematically evaluating the preoperative immune and nutritional status of patients and analyzing its prognostic impact on postoperative remnant gastric cancer (RGC) patients are crucial. A simple scoring system that combines multiple immune or nutritional indicators to identify nutritional or immune status before surgery is necessary.

AIM

To evaluate the value of preoperative immune-nutritional scoring systems in predicting the prognosis of patients with RGC.

METHODS

The clinical data of 54 patients with RGC were collected and analyzed retrospectively. Prognostic nutritional index (PNI), controlled nutritional status (CONUT), and Naples prognostic score (NPS) were calculated by preoperative blood indicators, including absolute lymphocyte count, lymphocyte to monocyte ratio, neutrophil to lymphocyte ratio, serum albumin, and serum total cholesterol. Patients with RGC were divided into groups according to the immune-nutritional risk. The relationship between the three preoperative immune-nutritional scores and clinical characteristics was analyzed. Cox regression and Kaplan–Meier analysis was performed to analyze the difference in overall survival (OS) rate between various immune-nutritional score groups.

RESULTS

The median age of this cohort was 70.5 years (ranging from 39 to 87 years). No significant correlation was found between most pathological features and immune-nutritional status (P > 0.05). Patients with a PNI score < 45, CONUT score or NPS score ≥ 3 were considered to be at high immune-nutritional risk. The areas under the receiver operating characteristic curves of PNI, CONUT, and NPS systems for predicting postoperative survival were 0.611 [95% confidence interval (CI): 0.460–0.763; P = 0.161], 0.635 (95%CI: 0.485–0.784; P = 0.090), and 0.707 (95%CI: 0.566–0.848; P = 0.009), respectively. Cox regression analysis showed that the three immune-nutritional scoring systems were significantly correlated with OS (PNI: P = 0.002; CONUT: P = 0.039; NPS: P < 0.001). Survival analysis revealed a significant difference in OS between different immune-nutritional groups (PNI: 75 mo vs 42 mo, P = 0.001; CONUT: 69 mo vs 48 mo, P = 0.033; NPS: 77 mo vs 40 mo, P < 0.001).

CONCLUSION

These preoperative immune-nutritional scores are reliable multidimensional prognostic scoring systems for predicting the prognosis of patients with RGC, in which the NPS system has relatively effective predictive performance.

The role of lipids in cancer progression and metastasis

Lipids have essential biological functions in the body (e.g., providing energy storage, acting as a signaling molecule, and being a structural component of membranes); however, an excess of lipids can promote tumorigenesis, colonization, and metastatic capacity of tumor cells. To metastasize, a tumor cell goes through different stages that require lipid-related metabolic and structural adaptations. These adaptations include altering the lipid membrane composition for invading other niches and overcoming cell death mechanisms and promoting lipid catabolism and anabolism for energy and oxidative stress protective purposes. Cancer cells also harness lipid metabolism to modulate the activity of stromal and immune cells to their advantage and to resist therapy and promote relapse. All this is especially worrying given the high fat intake in Western diets. Thus, metabolic interventions aiming to reduce lipid availability to cancer cells or to exacerbate their metabolic vulnerabilities provide promising therapeutic opportunities to prevent cancer progression and treat metastasis.

Inhibition of Scavenger Receptor Class B Type 1 (SR-B1) Expression and Activity as a Potential Novel Target to Disrupt Cholesterol Availability in Castration-Resistant Prostate Cancer

There have been several studies that have linked elevated scavenger receptor class b type 1 (SR-B1) expression and activity to the development and progression of castration-resistant prostate cancer (CRPC). SR-B1 facilitates the influx of cholesterol to the cell from lipoproteins in systemic circulation. This influx of cholesterol may be important for many cellular functions, including the synthesis of androgens. Castration-resistant prostate cancer tumors can synthesize androgens de novo to supplement the loss of exogenous sources often induced by androgen deprivation therapy. Silencing of SR-B1 may impact the ability of prostate cancer cells, particularly those of the castration-resistant state, to maintain the intracellular supply of androgens by removing a supply of cholesterol. SR-B1 expression is elevated in CRPC models and has been linked to poor survival of patients. The overarching belief has been that cholesterol modulation, through either synthesis or uptake inhibition, will impact essential signaling processes, impeding the proliferation of prostate cancer. The reduction in cellular cholesterol availability can impede prostate cancer proliferation through both decreased steroid synthesis and steroid-independent mechanisms, providing a potential therapeutic target for the treatment of prostate cancer. In this article, we discuss and highlight the work on SR-B1 as a potential novel drug target for CRPC management.

Organ-specific cholesterol metabolic aberration fuels liver metastasis of colorectal cancer

Rationale: Metastasis, the development of secondary malignant growth at a distance from a primary tumor, is the main cause of cancer-associated death. However, little is known about how metastatic cancer cells adapt to and colonize in the new organ environment. Here we sought to investigate the functional mechanism of cholesterol metabolic aberration in colorectal carcinoma (CRC) liver metastasis.

Methods: The expression of cholesterol metabolism-related genes in primary colorectal tumors (PT) and paired liver metastases (LM) were examined by RT-PCR. The role of SREBP2-dependent cholesterol biosynthesis pathway in cell growth and CRC liver metastasis were determined by SREBP2 silencing in CRC cell lines and experimental metastasis models including, intra-splenic injection models and liver orthotropic injection model. Growth factors treatment and co-culture experiment were performed to reveal the mechanism underlying the up-regulation of SREBP2 in CRC liver metastases. The in vivo efficacy of inhibition of cholesterol biosynthesis pathway by betulin or simvastatin were evaluated in experimental metastasis models.

Results: In the present study, we identify a colorectal cancer (CRC) liver metastasis-specific cholesterol metabolic pathway involving the activation of SREBP2-dependent cholesterol biosynthesis, which is required for the colonization and growth of metastatic CRC cells in the liver. Inhibiting this cholesterol biosynthesis pathway suppresses CRC liver metastasis. Mechanically, hepatocyte growth factor (HGF) from liver environment activates SREBP2-dependent cholesterol biosynthesis pathway by activating c-Met/PI3K/AKT/mTOR axis in CRC cells.

Conclusion: Our findings support the notion that CRC liver metastases show a specific cholesterol metabolic aberration. Targeting this cholesterol biosynthesis pathway could be a promising treatment for CRC liver metastasis.

Prognostic value of hypocholesterolemia in patients with gastric cancer

BACKGROUND

According to previous studies, low serum total cholesterol (TC) is associated with higher cancer incidence and mortality. However, the prognostic implications of preoperative TC in patients with gastric cancer (GC) remain to be determined.

METHODS

A total of 1251 patients with GC, who underwent radical gastrectomy between 2005 and 2008, were recruited. Propensity score weighting (PSW) based on a generalized boosted method (GBM) was used to control for selection bias.

RESULTS

After balancing the preoperative and operative covariates, low TC was associated with high incidence of complications (severe complication rate: 15.2% (Low TC) vs. 4.7% (Normal TC) vs 5.5% (High TC); p = 0.004). In multivariable analysis, lowering TC was associated with poor OS and RFS in weighted population. [OS: hazard ratio (HR) = 0.92; 95% CI = 0.867-0.980; P = 0.009 and RFS: HR = 0.93; 95% CI = 0.873-0.988; P = 0.02].

CONCLUSIONS

Preoperative TC is a useful predictor of postoperative survival and postoperative complications in patients with stage I-III GC and may help to identify high-risk patients for rational therapy, including nutritional support, and timely follow-up.